58CTA/CTX
2 --- St a g e De l u x e
In d u c e d --- Com b u st i on
4---Way Multipoise Furnace
Installation, Start---up, Operating and
Service and Maintenance
Instructions Series 130/D
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . . . . 2
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
CODES AND STANDARDS . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
General Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Combustion and Ventilation Air . . . . . . . . . . . . . . . . . . . . . . 5
Duct Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Acoustical Lining and Fibrous Glass Duct . . . . . . . . . . . . . . . 5
Gas Piping and Gas Pipe Pressure Testing . . . . . . . . . . . . . . . 5
Electrical Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Venting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
ama
ISO 9001:2000
CERTIFIED
ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS
PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
REGISTERED
LOCATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
AIR FOR COMBUSTION AND VENTILATION . . . . . . . . . 8
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
UPFLOW INSTALLATION . . . . . . . . . . . . . . . . . . . . . . 10
DOWNFLOW INSTALLATION . . . . . . . . . . . . . . . . . . . 11
HORIZONTAL INSTALLATION . . . . . . . . . . . . . . . . . . 11
FILTER ARRANGEMENT . . . . . . . . . . . . . . . . . . . . . . . 15
AIR DUCTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
GAS PIPING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
ELECTRICAL CONNECTIONS . . . . . . . . . . . . . . . . . . 21
VENTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
START--UP, ADJUSTMENT, AND SAFETY CHECK . . . . . 34
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Start--Up Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Check Safety Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
SERVICE AND MAINTENANCE PROCEDURES . . . . . 45
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Care and Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Sequence of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Wiring Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
NOTE: Read the entire instruction manual before starting the
installation.
Portions of the text and tables are reprinted from NFPA 54/ANSI
Z223.1--2006E, with permission of National Fire Protection
Association, Quincy, MA 02269 and American Gas Association,
Washington DC 20001. This reprinted material is not the
complete and official position of the NFPA or ANSI on the
referenced subject, which is represented only by the standard in
its entirety.
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Table 1 – Dimensions
F
FILTER
MEDIA
CABINET
IN (mm)
A
D
E
FLUE
COLLAR*
IN (mm)
C.L. TOP AND
BOTTOM FLUE
COLLAR
SHIP WT
LB (KG)
CABINET
WIDTH
IN (mm)
SUPPLY---AIR
WIDTH
RETURN---AIR
WIDTH
FURNACE SIZE
IN (mm)
IN (mm)
IN (mm)
045---08/024045
045---12/036045
070---08/024070
070---12/036070
070---16/048070
090---14/042090
090---16/048090
090---20/060090
110---12/036110
110---16/048110
110---22/066110
135---16/048135
135---22/066135
155---20/060155
14---3/16 (360)
14---3/16 (360)
14---3/16 (360)
14---3/16 (360)
17---1/2 (445)
17---1/2 (445)
21 (533)
21 (533)
17---1/2 (445)
21 (533)
12---9/16 (319)
12---9/16 (319)
12---9/16 (319)
12---9/16 (319)
15---7/8 (403)
15---7/8 (403)
19---3/8 (492)
19---3/8 (492)
15---7/8 (403)
19---3/8 (492)
19---3/8 (492)
19---3/8 (492)
22---7/8 (581)
22---7/8 (581)
12---11/16 (322)
12---11/16 (322)
12---11/16 (322)
12---11/16 (322)
16 (406)
9---5/16 (237)
9---5/16 (237)
9---5/16 (237)
9---5/16 (237)
11---9/16 (294)
11---9/16 (294)
13---5/16 (338)
13---5/16 (338)
11---9/16 (294)
13---5/16 (338)
13---5/16 (338)
13---5/16 (338)
15---1/16 (383)
15---1/16 (383)
4 (102)
4 (102)
4 (102)
4 (102)
4 (102)
4 (102)
4 (102)
4 (102)
4 (102)
4 (102)
4 (102)
4 (102)
4 (102)
4 (102)
104 (47)
107 (48)
111 (50)
115 (52)
126 (57)
127 (58)
140 (64)
146 (66)
135 (61)
146 (66)
152 (69)
149 (68)
163 (74)
170 (77)
16 (406)
16 (406)
16 (406)
16 (406)
16 (406)
16 (406)
20 (508)
20 (508)
16 (406)
20 (508)
20 (508)
20 (508)
24 (610)
24 (610)
16 (406)
19---1/2 (495)
19---1/2 (495)
16 (406)
19---1/2 (495)
19---1/2 (495)
19---1/2 (495)
23 (584)
21 (533)
21 (533)
24---1/2 (622)
24---1/2 (622)
23 (584)
* 5---in. or 6---in. (127 or 152 mm) vent connector may be required in some cases.
{ 135 and 155 size furnaces require 5---in. (127 mm) or larger vents. Use a 4 to 5 or 4 to 6---in. (102 to 127 or 102 to 152 mm) vent adapter between furnace and
vent connector.
product and property damage. NOTE is used to highlight
suggestions which will result in enhanced installation, reliability,
or operation.
11. See Fig. 2 for required clearances to combustible construc-
tion.
12. Maintain a 1--in. (25 mm) clearance from combustible ma-
terials to supply air ductwork for a distance of 36 inches
(914 mm) horizontally from the furnace. See NFPA 90B
or local code for further requirements.
1. Use only with type of gas approved for this furnace. Refer
to the furnace rating plate 2. Install this furnace only in a
2. Install this furnace only in a location and position as spe-
cified in the “Location” section of these instructions.
13. These furnaces SHALL NOT be installed directly on car-
peting, tile, or any other combustible material other than
wood flooring. In downflow installations, factory access-
ory floor base MUST be used when installed on combust-
ible materials and wood flooring. Special base is not re-
quired when this furnace is installed on manufacturer’s
Coil Assembly Part No. CAR, CAP, CNRV, CNPV or
when Coil Box Part No. KCAKC is used. See Fig. 2 for
clearance to combustible construction information.
3. Provide adequate combustion and ventilation air to the
furnace space as specified in “Air for Combustion and
Ventilation” section.
4. Combustion products must be discharged outdoors. Con-
nect this furnace to an approved vent system only, as spe-
cified in the “Venting” section of these instructions.
5. Never test for gas leaks with an open flame. Use a com-
mercially available soap solution made specifically for the
detection of leaks to check all connections, as specified in
the “Gas Piping” section.
INTRODUCTION
The Series 130/D 4--way multipoise Category I fan--assisted
furnace is CSA (formerly A.G.A.. and C.G.A.) design--certified.
A Category I fan--assisted furnace is an appliance equipped with
an integral mechanical means to either draw or force products of
combustion through the combustion chamber and/or heat
exchanger. The furnace is factory--shipped for use with natural
gas. This furnace is not approved for installation in mobile
homes, recreational vehicles, or outdoors.
6. Always install furnace to operate within the furnace’s in-
tended temperature--rise range with a duct system which
has an external static pressure within the allowable range,
as specified in the “Start--Up, Adjustments, and Safety
Check” section. See furnace rating plate.
7. When a furnace is installed so that supply ducts carry air
circulated by the furnace to areas outside the space con-
taining the furnace, the return air shall also be handled by
duct(s) sealed to the furnace casing and terminating out-
side the space containing the furnace. See “Air Ducts” sec-
tion.
8. A gas--fired furnace for installation in a residential garage
must be installed as specified in the warning box in the
“Location” section.
These furnaces shall not be installed directly on carpeting, tile, or
any other combustible material other than wood flooring. For
downflow installations, a factory accessory floor base must be
used when installed on combustible materials and wood flooring.
This special base is not required when this furnace is installed on
the manufacturer’s coil assembly, or when the manufacturer’s coil
box is used. See Fig. 2 for clearance to combustible material
information.
9. The furnace may be used for construction heat provided
that the furnace installation and operation complies with
the first CAUTION in the LOCATION section of these in-
structions.
10. These Multipoise Gas--Fired Furnaces are CSA (formerly
A.G.A. and C.G.A.) design--certified for use with natural
and propane gases (see furnace rating plate) and for install-
ation in alcoves, attics, basements, closets, utility rooms,
crawlspaces, and garages. The furnace is factory--shipped
for use with natural gas. A CSA (A.G.A. and C.G.A.) lis-
ted accessory gas conversion kit is required to convert fur-
nace for use with propane gas.
This furnace is designed for minimum continuous return--air
temperature of 60_F (16_C) db or intermittent operation down to
55_F (13_C) db such as when used with a night setback
thermostat. Return--air temperature must not exceed 80_F (27_C)
db. Failure to follow these return--air temperature limits may
affect reliability of heat exchangers, motors, and controls. (See
Fig. 3.)
For accessory installation details, refer to the applicable
instruction literature.
NOTE: Remove all shipping brackets and materials before
operating the furnace.
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A08471
Fig. 2 -- Clearances to Combustibles
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90B as tested by UL Standard 181 for Class I Rigid Air Ducts
80 / 27 C
Step 6 — Gas Piping and Gas Pipe Pressure Testing
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US: NFPA 54 / ANSI Z223.1--2006; chapters 5, 6, 7, and 8 and
National Plumbing Codes
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CANADA: CAN/CSA--B149.1--05 Parts 4, 5, and 6 and
Appendices A, B, E and H.
Step 7 — Electrical Connections
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US: National Electrical Code (NEC) ANSI/NFPA 70--2008
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CANADA: Canadian Electrical Code CSA C22.1
Step 8 — Venting
60 / 16 C
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US: NFGC; NFPA 54 / ANSI Z223.1--2006 chapters 12 and 13
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CANADA: CAN/CSA--B149.1--05 Part 8 and Appendix C
ELECTROSTATIC DISCHARGE (ESD)
PRECAUTIONS PROCEDURE
A06745
Fig. 3 -- Return Air Temperature
!
CAUTION
CODES AND STANDARDS
FURNACE RELIABILITY HAZARD
Follow all national and local codes and standards in addition
to these instructions. The installation must comply with
regulations of the serving gas supplier, local building, heating,
plumbing, and other codes. In absence of local codes, the
installation must comply with the national codes listed below and
all authorities having jurisdiction.
Improper installation or service of furnace may cause
premature furnace component failure.
Electrostatic discharge can affect electronic components.
Follow the Electrostatic Discharge Precautions Procedure
listed below during furnace installation and servicing to
protect the furnace electronic control. Precautions will
prevent electrostatic discharges from personnel and hand
tools which are held during the procedure. These
precautions will help to avoid exposing the control to
electrostatic discharge by putting the furnace, the control,
and the person at the same electrostatic potential.
In the United States and Canada, follow all codes and standards
for the following:
Step 1 — Safety
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US: National Fuel Gas Code (NFGC) NFPA 54--2006/ANSI
Z223.1--2006 and the Installation Standards, Warm Air Heating
and Air Conditioning Systems ANSI/NFPA 90B
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CANADA: CSA B149.1--05 National Standard of Canada
1. Disconnect all power to the furnace. Multiple disconnects
may be required. DO NOT TOUCH THE CONTROL OR
ANY WIRE CONNECTED TO THE CONTROL PRIOR
Natural
Gas
and
Propane
Installation
Code
(CAN/CSA--B149.1--05)
TO
DISCHARGING
YOUR
BODY’S
Step 2 — General Installation
ELECTROSTATIC CHARGE TO GROUND.
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US: Current edition of the NFGC and the NFPA 90B. For
copies, contact the National Fire Protection Association Inc.,
only the NFGC, contact the American Gas Association, 400 N.
Capitol Street, N.W., Washington DC 20001 (www.AGA.org.)
2. Firmly touch the clean, unpainted, metal surface of the fur-
nace chassis which is close to the control. Tools held in a
person’s hand during grounding will be satisfactorily dis-
charged.
3. After touching the chassis, you may proceed to service the
control or connecting wires as long as you do nothing to
recharge your body with static electricity (for example;
DO NOT move or shuffle your feet, do not touch un-
grounded objects, etc.).
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CANADA: CAN/CSA--B149.1--05. For a copy, contact
Standard Sales, CSA International, 178 Rexdale Boulevard,
Etobicoke (Toronto), Ontario, M9W 1R3 Canada Step
Step 3 — Combustion and Ventilation Air
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US: Section 9.3 of the NFGC, NFPA 54/ ANSI Z223.1--2006
Air for Combustion and Ventilation
4. If you touch ungrounded objects (and recharge your body
with static electricity), firmly touch a clean, unpainted
metal surface of the furnace again before touching control
or wires.
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CANADA: Part 8 of CAN/CSA--B149.1--05, Venting Systems
and Air Supply for Appliances
5. Use this procedure for installed and uninstalled (ungroun-
ded) furnaces.
Step 4 — Duct Systems
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US and CANADA: Air Conditioning Contractors Association
(ACCA) Manual D, Sheet Metal and Air Conditioning
Contractors National Association (SMACNA), or American
Society of Heating, Refrigeration, and Air Conditioning
Engineers (ASHRAE) 2001 Fundamentals Handbook Chapter
34 or 2000 HVAC Systems and Equipment Handbook Chapters
9 and 16.
6. Before removing a new control from its container, dis-
charge your body’s electrostatic charge to ground to pro-
tect the control from damage. If the control is to be in-
stalled in a furnace, follow items 1 through 4 before
bringing the control or yourself in contact with the fur-
nace. Put all used and new controls into containers before
touching ungrounded objects.
Step 5 — Acoustical Lining and Fibrous Glass Duct
7. An ESD service kit (available from commercial sources)
may also be used to prevent ESD damage.
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US and CANADA: current edition of SMACNA and NFPA
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THE BLOWER IS
LOCATED BELOW THE
BURNER SECTION, AND
CONDITIONED AIR IS
DISCHARGED UPWARD.
THE BLOWER IS LOCATED
TO THE RIGHT OF THE
BURNER SECTION, AND
AIR CONDITIONED AIR IS
DISCHARGED TO THE LEFT.
THE BLOWER IS
THE BLOWER IS
LOCATED ABOVE THE
BURNER SECTION, AND
CONDITIONED AIR IS
DISCHARGED DOWNWARD
LOCATED TO THE LEFT
OF THE BURNER SECTION,
AND CONDITIONED AIR IS
DISCHARGED TO THE RIGHT.
A02097
Fig. 4 -- Multipoise Orientations
The following types of furnace installations may require
OUTDOOR AIR for combustion due to chemical exposures:
LOCATION
GENERAL
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Commercial buildings
Buildings with indoor pools
Laundry rooms
This multipoise furnace is shipped in packaged configuration.
Some assembly and modifications are required when used in any
of the four applications shown in Fig. 4.
Hobby or craft rooms, and
Chemical storage areas
NOTE:
For high--altitude installations, the high--altitude
conversion kit MUST be installed at or above 5500 ft. (1676 M)
above sea level. Obtain high--altitude conversion kit from your
area authorized distributor.
If air is exposed to the following substances, it should not be used
for combustion air, and outdoor air may be required for
combustion:
This furnace must:
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be installed so the electrical components are protected from
water.
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Permanent wave solutions
Chlorinated waxes and cleaners
Chlorine based swimming pool chemicals
Water softening chemicals
not be installed directly on any combustible material other than
wood flooring (refer to SAFETY CONSIDERATIONS).
be located close to the chimney or vent and attached to an air
distribution system. Refer to Air Ducts section.
De--icing salts or chemicals
Carbon tetrachloride
be provided ample space for servicing and cleaning. Always
comply with minimum fire protection clearances shown on the
furnace clearance to combustible construction label.
Halogen type refrigerants
Cleaning solvents (such as perchloroethylene)
Printing inks, paint removers, varnishes, etc.
Hydrochloric acid
!
WARNING
CARBON MONOXIDE POISONING AND UNIT
DAMAGE HAZARD
Cements and glues
Antistatic fabric softeners for clothes dryers
S
Masonry acid washing materials
Failure to follow this warning could result in personal
injury or death, and furnace damage.
All fuel--burning equipment must be supplied with air for fuel
combustion. Sufficient air must be provided to avoid negative
pressure in the equipment room or space. A positive seal must be
made between the furnace cabinet and the return--air duct to
prevent pulling air from the burner area and from draft safeguard
opening.
Corrosive or contaminated air may cause failure of parts
containing flue gas, which could leak into the living space.
Air for combustion must not be contaminated by halogen
compounds, which include fluoride, chloride, bromide, and
iodide. These elements can corrode heat exchangers and
shorten furnace life. Air contaminants are found in aerosol
sprays, detergents, bleaches, cleaning solvents, salts, air
fresheners, and other household products. Do not install
furnace in a corrosive or contaminated atmosphere. Make
sure all combustion and circulating air requirements are met,
in addition to all local codes and ordinances.
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!
WARNING
FIRE, INJURY OR DEATH HAZARD
Failure to follow this warning could result in personal
injury, death, and/or property damage.
When the furnace is installed in a residential garage, the
burners and ignition sources must be located at least 18
inches (457 mm) above the floor. The furnace must be
located or protected to avoid damage by vehicles. When the
furnace is installed in a public garage, airplane hangar, or
other building having a hazardous atmosphere, the furnace
must be installed in accordance with the NFGC or
CAN/CSA--B149.1--05. (See Fig. 5.)
A02054
Fig. 6 -- Prohibit Installation on Back
!
CAUTION
PROPERTY DAMAGE HAZARD
Improper use or installation of this furnace may cause
premature component failure. This gas furnace may be used
for construction heat provided that:
--The furnace is permanently installed with all electrical
wiring, piping, venting and ducting installed according to
these installation instructions. A return air duct is provided,
sealed to the furnace casing, and terminated outside the
space containing the furnace. This prevents a negative
pressure condition as created by the circulating air blower,
causing a flame roll--out and/or drawing combustion
products into the structure.
18-IN. (457.2 mm)
MINIMUM TO BURNERS
--The furnace is controlled by a thermostat. It may not be
”hot wired” to provide heat continuously to the structure
without thermostatic control.
A93044
Fig. 5 -- Installation in a Garage
--Clean outside air is provided for combustion. This is to
minimize the corrosive effects of adhesives, sealers and
other construction materials. It also prevents the
entrainment of drywall dust into combustion air, which can
cause fouling and plugging of furnace components.
--The temperature of the return air to the furnace is
maintained between 55_F (13_C) and 80_F (27_C), with
no evening setback or shutdown. The use of the furnace
while the structure is under construction is deemed to be
intermittent operation per our installation instructions.
--The air temperature rise is within the rated rise range on
the furnace rating plate, and the gas input rate has been set
to the nameplate value.
!
WARNING
FIRE HAZARD
Failure to follow this warning could result in personal
injury, death and/or property damage.
Do not install the furnace on its back or hang furnace with
control compartment facing downward. Safety control
operation will be adversely affected. Never connect
return--air ducts to the back of the furnace. (See Fig. 6.)
--The filters used to clean the circulating air during the
construction process must be either changed or thoroughly
cleaned prior to occupancy.
--The furnace, ductwork and filters are cleaned as necessary
to remove drywall dust and construction debris from all
HVAC system components after construction is completed.
--Verify proper furnace operating conditions including
ignition, gas input rate, air temperature rise, and venting
according to these installation instructions.
LOCATION RELATIVE TO COOLING EQUIPMENT
The cooling coil must be installed parallel with, or on the
downstream side of the unit to avoid condensation in the heat
exchangers. When installed parallel with the furnace, dampers or
other flow control must prevent chilled air from entering the
furnace. If the dampers are manually operated, they must be
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equipped with means to prevent operation of either unit unless
the damper is in the full--heat or full--cool position.
The requirements for combustion and ventilation air depend upon
whether or not the furnace is located in a space having a volume
of at least 50 cubic feet per 1,000 Btuh input rating for all gas
appliances installed in the space.
AIR FOR COMBUSTION AND
VENTILATION
Provisions for adequate combustion, ventilation, and dilution air
must be provided in accordance with:
U.S. installations: Section 9.3 of the NFPA 54 /A ANSI
Z223.1--2006, Air for Combustion and Ventilation, and
applicable provisions of the local building codes.
S
Spaces having less than 50 cubic feet per 1,000 Btuh require the
Outdoor Combustion Air Method.
S
Spaces having at least 50 cubic feet per 1,000 Btuh may use the
Indoor Combustion Air, Standard or Known Air Infiltration
Method.
Outdoor Combustion Air Method
1. Provide the space with sufficient air for proper combus-
tion, ventilation, and dilution of flue gases using perman-
ent horizontal or vertical duct(s) or opening(s) directly
communicating with the outdoors or spaces that freely
communicate with the outdoors.
Canadian installations: Part 8 of the CAN/CSA--B149.1--05,
Venting Systems and Air Supply for Appliances and all
authorities having jurisdiction.
!
CAUTION
2. Fig. 7 illustrates how to provide TWO OUTDOOR
OPENINGS, one inlet and one outlet combustion and
ventilation air opening, to the outdoors.
FURNACE CORROSION HAZARD
Failure to follow this caution may result in furnace damage.
a. One opening MUST commence within 12 in. (300 mm)
of the ceiling and the second opening MUST commence
within 12 in. (300 mm) of the floor.
Air for combustion must not be contaminated by halogen
compounds, which include fluoride, chloride, bromide, and
iodide. These elements can corrode heat exchangers and
shorten furnace life. Air contaminants are found in aerosol
sprays, detergents, bleaches, cleaning solvents, salts, air
fresheners, and other household products.
b. Size openings and ducts per Fig. 7 and Table 2.
2
c. TWOHORIZONTALDUCTSrequire1 --in of freearea
2
per 2,000 Btuh (1,100 mm /kW) of combined input for
all gas appliances in the space per Fig. 7 and Table 2.
d. TWO OPENINGS OR VERTICAL DUCTS require 1
2
2
-- i n of free area per 4,000 Btuh (550 mm /kW) for com-
bined input of all gas appliances in the space per Fig. 7
and Table 2.
!
WARNING
CARBON MONOXIDE POISONING HAZARD
3. ONE OUTDOOR OPENING requires:
a. One square inch of free area per 3,000 Btuh (734
mm /kW) for combined input of all gas appliances in the
space per Table 2 and
b. Not less than the sum of the areas of all vent connectors
in the space.
Failure to follow this warning could result in personal
injury or death.
2
The operation of exhaust fans, kitchen ventilation fans,
clothes dryers, attic exhaust fans or fireplaces could create a
NEGATIVE PRESSURE CONDITION at the furnace.
Make--up air MUST be provided for the ventilation devices,
in addition to that required by the furnace. Refer to Carbon
Monoxide Poisoning Hazard warning in venting section of
these instructions to determine if an adequate amount of
make--up air is available.
Table 2 – Minimum Free Area Required for Each Combustion Air opening of Duct to Outdoors
TWO HORIZONTAL DUCTS
(1 SQ. IN./2,000 BTUH) (1,100 SQ. MM/KW)
SINGLE DUCT OR OPENING
(1 SQ. IN./3,000 BTUH) (734 SQ. MM/KW)
TWO OPENINGS OR VERTICAL DUCTS
(1 SQ. IN./4,000 BTUH) (550 SQ. MM/KW)
FURNACE
INPUT
(BTUH)
Free Area of Opening
and Duct
Sq. In. (Sq. mm)
Round Duct
Dia.
In. (mm)
Free Area of Opening
and Duct
Sq. In. (Sq. mm)
Round Duct
Dia.
In. (mm)
Free Area of Opening
and Duct
Sq. In. (Sq. mm)
Round Duct
Dia.
In. (mm)
44,000
66,000
88,000
110,000
132,000
154,000
22 (14194)
33 (21290)
44 (28387)
55 (35484)
66 (42580)
77 (49677)
6 (152)
7 (178)
8 (203)
9 (229)
10 (254)
10 (254)
14.7 (9484)
22 (14193)
29.3 (18903)
36.7 (23677)
44 (28387)
5 (127)
6 (152)
7 (178)
7 (178)
8 (203)
9 (229)
11 (7096)
16.5 (10645)
22 (14193)
27.5 (17742)
33 (21290)
38.5 (24839)
4 (102)
5 (127)
6 (152)
6 (152)
7 (178)
8 (203)
51.3 (33096)
EXAMPLES: Determining Free Area
FURNACE
WATER HEATER
TOTAL INPUT
110,000
66,000
88,000
+
+
+
30,000
40,000
30,000
=
=
=
(140,000 divided by 4,000)
(106,000 divided by 3,000)
(118,000 divided by 2,000)
=
=
=
35.0 Sq. In. for each two Vertical Ducts or Openings
35.3 Sq. In. for a Single Duct or Opening
59.0 Sq. In. for each of two Horizontal Ducts
8
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1 SQ IN.
PER 4000
BTUH*
CIRCULATING AIR
DUCTS
VENT THROUGH ROOF
DUCTS
TO
OUTDOORS
12" MAX(305mm)
(305mm)
12″ MAX
D
12″
(305mm)
MAX
1 SQ IN.
PER 2000
BTUH*
VENT
1 SQ IN.
B
THROUGH
ROOF
F
PER 1000
BTUH* IN DOOR
OR WALL
1 SQ IN.
PER
4000
BTUH*
UNCONFINED
SPACE
INTERIOR
HEATED
SPACE
DUCTS
TO
OUTDOORS
6" MIN (152mm)
(FRONT)Ü
1 SQ IN.
1 SQ IN.
PER
PER 1000
BTUH* IN DOOR
OR WALL
4000
BTUH*
1 SQ IN.
PER 2000
BTUH*
E
G
A
12" MAX
12″
MAX
(305mm)
(305mm)
(305mm)
12″ MAX
C
12″ MAX
(305mm)
CIRCULATING AIR DUCTS
CIRCULATING AIR DUCTS
DUCT
TO
OUTDOORS
1 SQ IN.
PER 4000
BTUH*
* Minimum opening size is 100 sq in. (64516 sq. mm) with minimum
dimensions of 3 in. (76 mm)
† Minimum of 3 in. (76 mm) when type-B1 vent is used.
*Minimum dimensions of 3---in. (76 mm).
Note: Use any of the following combinations of openings:
A & B C & D D & E F & G
A03175
A03174
Fig. 8 -- Air for Combustion, Ventilation, and Dilution from
Indoors
Fig. 7 -- Air for Combustion, Ventilation, and Dilution for
Outdoors
The Standard Method:
The opening shall commence within 12 in. (300 mm) of the
ceiling. Appliances in the space shall have clearances of at least 1
in. (25 mm) from the sides and back and 6 in. (150 mm) from the
front. The opening shall directly communicate with the outdoors
or shall communicate through a vertical or horizontal duct to the
outdoors or spaces (crawl or attic) that freely communicate with
the outdoors.
1. The space has no less volume than 50 cubic feet per 1,000
Btuh of the maximum input ratings for all gas appliances
installed in the space and
2. The air infiltration rate is not known to be less than 0.40
air changes per hour (ACH).
The Known Air Infiltration Rate Method shall be used, if the
infiltration rate is known to be:
Indoor Combustion AirE NFPA & AGA Standard and
Known--Air--Infiltration Rate Methods
1. Less than 0.40 ACH and
2. Equal to or greater than 0.10 ACH
Indoor air is permitted for combustion, ventilation, and dilution,
if the Standard or Known--Air--Infiltration Method is used.
Infiltration rates greater than 0.60 ACH shall not be used. The
minimum required volume of the space varies with the number of
ACH and shall be determined per Table 3 or Equations 1 and 2.
Determine the minimum required volume for each appliance in
the space and add the volumes together to get the total minimum
required volume for the space.
!
WARNING
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in death and/or
personal injury.
Many homes require air to be supplied from outdoors for
furnace combustion, ventilation, and dilution of flue gases.
The furnace combustion air supply must be provided in
accordance with this instruction manual.
9
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Table 3 – Minimum Space Volumes for 100% Combustion, Ventilation, and Dilution from Indoors
OTHER THAN FAN---ASSISTED TOTAL
(1,000s BTUH GAS INPUT RATE)
FAN---ASSISTED TOTAL
(1,000s BTUH GAS INPUT RATE)
ACH
30
40
50
44
66
88
110
132
154
Space Volume (ft.3)
0.60
0.50
0.40
0.30
0.20
0.10
0.00
1,050
1,260
1,575
2,100
3,150
6,300
NP
1,400
1,680
2,100
2,800
4,200
8,400
NP
1,750
2,100
2,625
3,500
5,250
10,500
NP
1,100
1,320
1,650
2,200
3,300
6,600
NP
1,650
2,200
2,640
3,300
4,400
6,600
13,200
NP
2,750
3,300
4,125
5,500
8,250
16,500
NP
3,300
3,960
4,950
6,600
9,900
19,800
NP
3,850
4,620
5,775
7,700
11,550
23,100
NP
1,980
2,475
3,300
4,950
9,900
NP
NP = Not Permitted
Table 3--Minimum Space Volumes were determined by using
the following equations from the National Fuel Gas Code ANSI
Z223.1--2006/NFPA 54--2006, 9.3.2.2:
However, in buildings with unusually tight construction,
additional air MUST be provided using the methods de-
scribed in the Outdoor Combustion Air Method section.
Unusually tight construction is defined as Construction
with:
1. For other than fan--assisted appliances, such as a draft
hood--equipped water heater:
a. Walls and ceilings exposed to the outdoors have a con-
tinuous, sealed vapor barrier. Openings are gasketed or
sealed and
21ft3
I other
ACH 1000 Btu/hr
Volume
=
Other
b. Doors and openable windows are weatherstripped and
c. Other openings are caulked or sealed. These include
joints around window and door frames, between sole
plates and floors, between wall--ceiling joints, between
wall panels, at penetrations for plumbing, electrical and
gas lines, etc.
A04002
2. For fan--assisted appliances such as this furnace:
15ft3
I fan
Volume
=
Combination of Indoor and Outdoor Air
Fan
ACH 1000 Btu/hr
1. Indoor openings shall comply with the Indoor Combus-
tion Air Method below and,
A04003
If:
I
2. Outdoor openings shall be located as required in the Out-
door Combustion Air Method mentioned previously and,
3. Outdoor openings shall be sized as follows:
=
=
=
combined input of all other than fan--assisted
appliances in Btuh/hr
combined input of all fan--assisted appliances in
other
I
fan
a. Calculate the Ratio of all Indoor Space volume divided
by required volume for Indoor Combustion Air Meth-
od below.
Btuh/hr
ACH
air changes per hour (ACH shall not exceed 0.60.)
b. Outdoor opening size reduction Factor is 1 minus the
Ratio in a. above.
c. Minimum size of Outdoor openings shall be the size re-
quired in Outdoor Combustion AirMethod abovemul-
tiplied by reduction Factor in b. above. The minimum
dimension of air openings shall be not less than 3 in. (80
mm).
The following requirements apply to the Standard Method and
to the Known Air Infiltration Rate Method.
1. Adjoining rooms can be considered part of a space if:
a. There are no closeable doors between rooms.
b. Combining spaces on same floor level. Each opening
2
shall have free area of at least 1 in. /1,000 Btuh (2,000
2
mm /kW) of the total input rating of all gas appliances
INSTALLATION
UPFLOW INSTALLATION
2
2
in the space, but not less than 100 in. (0.06 m ). One
opening shall commence within 12 in. (300 mm) of the
ceiling and the second opening shall commence within
12 in. (300 mm) of the floor. The minimum dimension
of air openings shall be at least 3 in. (80 mm). (See Fig.
8.)
Bottom Return Air Inlet
These furnaces are shipped with bottom closure panel installed in
bottom return--air opening. Remove and discard this panel when
bottom return air is used. To remove bottom closure panel,
perform the following:
c. Combining space on different floor levels. The volumes
of spaces on different floor levels shall be considered as
communicating spaces if connected by one or more per-
manent openings in doors or floors having free area of
1. Tilt or raise furnace and remove 2 screws holding bottom
filler panel. (See Fig. 9.)
2. Rotate bottom filler panel downward to release holding
tabs.
2
2
at least 2 in. /1,000 Btuh (4,400 mm /kW) of total input
rating of all gas appliances.
3. Remove bottom closure panel.
4. Reinstall bottom filler panel and screws.
Side Return Air Inlet
2. An attic or crawlspace may be considered a space that
freely communicates with the outdoors provided there are
adequate permanent ventilation openings directly to out-
doors having free area of at least 1--in.2/4,000 Btuh of
total input rating for all gas appliances in the space.
3. In spaces that use the Indoor Combustion Air Method, in-
filtration should be adequate to provide air for combus-
tion, permanent ventilation and dilution of flue gases.
These furnaces are shipped with bottom closure panel installed in
bottom return--air opening. This panel MUST be in place when
only side return air is used.
10
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NOTE: Side return--air openings can be used in UPFLOW and
most HORIZONTAL configurations. Do not use side return--air
openings in DOWNFLOW configuration.
DOWNFLOW INSTALLATION
NOTE: For downflow applications, this furnace is approved for
use on combustible flooring when any one of the following 3
accessories are used:
S
S
S
Special Base, KGASB
Cased Coil Assembly Part No. CNPV, CNRV, CAP, and CAR
Coil Box Part No. KCAKC
1. Determine application being installed from Table 4.
2. Construct hole in floor per Table 4 and Fig. 11.
3. Construct plenum to dimensions specified in Table 4 and
Fig. 11.
4. If downflow subbase, KGASB is used, install as shown in
Fig. 12. If Coil Assembly Part No. CNPV, CNRV, CAP,
CAR or Coil Box Part No. KCAKC is used, install as
shown in Fig. 13.
NOTE: It is recommended that the perforated supply--air duct
flanges be completely folded over or removed from furnace when
installing the furnace on a factory--supplied cased coil or coil box.
To remove the supply--air duct flange, use wide duct pliers or
hand seamers to bend flange back and forth until it breaks off. Be
careful of sharp edges. (See Fig. 14.)
A02098
Fig. 9 -- Removing Bottom Closure Panel
Leveling Legs (If Desired)
In upflow position with side return inlet(s), leveling legs may be
used. (See Fig. 10.) Install field--supplied, 5/16 x 1--1/2 in. (8 x
38 mm) (max) corrosion--resistant machine bolts, washers and
nuts.
NOTE: Bottom closure must be used when leveling legs are
used. It may be necessary to remove and reinstall bottom closure
panel to install leveling legs. To remove bottom closure panel, see
item 1 in Bottom Return Air Inlet section in Step 1 above.
Bottom Return Air Inlet
These furnaces are shipped with bottom closure panel installed in
bottom return--air opening. Remove and discard this panel when
bottom return air is used. To remove bottom closure panel,
perform the following:
1. Tilt or raise furnace and remove 2 screws holding bottom
filler panel. (See Fig. 9.)
2. Rotate bottom filler panel downward to release holding
tabs.
3. Remove bottom closure panel.
4. Reinstall bottom filler panel and screws.
HORIZONTAL INSTALLATION
To install leveling legs:
1. Position furnace on its back. Locate and drill a hole in
each bottom corner of furnace. (See Fig. 10.)
2. For each leg, install nut on bolt and then install bolt and
nut in hole. (Install flat washer if desired.)
The furnace can be installed horizontally in an attic or crawl space
on either the left--hand (LH) or right--hand (RH) side. The furnace
can be hung from floor joists, rafters or trusses or installed on a
non--combustible platform, blocks, bricks or pad.
3. Install another nut on other side of furnace base. (Install
flat washer if desired.)
4. Adjust outside nut to provide desired height, and tighten
inside nut to secure arrangement.
5. Reinstall bottom closure panel if removed.
!
WARNING
5/
16″
(8mm)
FIRE, EXPLOSION, AND CARBON MONOXIDE
POISONING HAZARD
(8mm)
5/
16″
Failure to follow this warning could result in personal
injury, death, or property damage.
1 3/4
″
Do not install the furnace on its back or hang furnace with
control compartment facing downward. Safety control
operation will be adversely affected. Never connect
return--air ducts to the back of the furnace.
(44mm)
1 3/4
″
(44mm)
Suspended Furnace Support
The furnace may be supported under each end with threaded rod,
angle iron or metal plumber’s strap as shown. (See Fig. 15 and
16.) Secure angle iron to bottom of furnace as shown.
Heavy--gauge sheet metal straps (plumber’s straps) may be used
to suspend the furnace from each bottom corner. To prevent
screws from pulling out, use 2 #8 x 3/4--in. (19 mm) screw into
the side and 2 #8 x 3/4--in. (19 mm) screw in the bottom of the
furnace casing for each strap. (See Fig. 15 and 16.)
If the screws are attached to ONLY the furnace sides and not the
bottom, the straps must be vertical against the furnace sides and
not pull away from the furnace sides, so that the strap attachment
screws are not in tension (are loaded in shear) for reliable support.
(8mm)
5/16″
(8mm)
5/
16″
(44mm)1 3/
1 3/
4″
4
″
(44mm)
A89014
Fig. 10 -- Leveling Legs
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Platform Furnace Support
FURNACE
(OR COIL CASING
WHEN USED)
Construct working platform at location where all required furnace
clearances are met. (See Fig. 2 and 17.) For furnaces with 1--in.
(25 mm) clearance requirement on side, set furnace on
non--combustible blocks, bricks or angle iron. For crawlspace
installations, if the furnace is not suspended from the floor joists,
the ground underneath furnace must be level and the furnace set
on blocks or bricks.
COMBUSTIBLE
FLOORING
Roll--Out Protection
Provide a minimum 17--3/4--in. x 22--in. (451 x 559 mm) piece of
sheet metal for flame roll--out protection in front of burner area
for furnaces closer than 12 inches (305 mm) above the
combustible deck or suspended furnaces closer than 12 inches
(305 mm) to joists. The sheet metal MUST extend underneath the
furnace casing by 1 in. (25 mm) with the door removed.
The bottom closure panel on furnaces of widths 17--1/2 in. (445
mm) and larger may be used for flame roll--out protection when
bottom of furnace is used for return air connection. See Fig. 17
for proper orientation of roll--out shield.
DOWNFLOW
SUBBASE
SHEET METAL
PLENUM
FLOOR
OPENING
Bottom Return Air Inlet
These furnaces are shipped with bottom closure panel installed in
bottom return--air opening. Remove and discard this panel when
bottom return air is used. To remove bottom closure panel,
perform the following:
1. Tilt or raise furnace and remove 2 screws holding bottom
filler panel. (See Fig. 9.)
2. Rotate bottom filler panel downward to release holding
tabs.
A96285
Fig. 12 -- Furnace, Plenum, and Subbase installed on a
Combustible Floor
3. Remove bottom closure panel.
4. Reinstall bottom filler panel and screws.
Side Return Air Inlet
FURNACE
APPROVED
COIL ASSEMBLY
OR
These furnaces are shipped with bottom closure panel installed in
bottom return--air opening. This panel MUST be in place when
side return air inlet(s) are used without a bottom return air inlet.
COIL BOX
COMBUSTIBLE
FLOORING
SHEET METAL
PLENUM
A
PLENUM
OPENING
FLOOR
OPENING
B
D
FLOOR
OPENING
C
A08556
Fig. 13 -- Furnace, Plenum, and Coil Assembly or Coil Box
Installed on a Combustible Floor
A96283
Fig. 11 -- Floor and Plenum Opening Dimensions
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Table 4 – Opening dimensions -- In. (mm)
PLENUM OPENING
FURNACE
CASING
WIDTH
FLOOR OPENING
APPLICATION
A
B
C
D
Upflow Applications on Combustible or Noncombustible Floor-
ing (KGASB subbase not required)
12---11/16
(322)
21---5/8
(549)
19
(483)
19
(483)
13---5/16
(338)
22---1/4
(565)
Downflow Applications on Noncombustible Flooring (KGASB
subbase not required)
12---9/16
(319)
13---3/16
(335)
19---5/8
(498)
14–3/16
(376)
Downflow applications on combustible flooring (KGASB sub-
base required)
11---13/16
(284)
13---7/16
(341)
20---5/8
(600)
Downflow Applications on Combustible Flooring with CNPV,
CNRV, CAR, or CAP Coil Assembly or KCAKC coil box
(KGASB subbase not required)
12---5/16
(319)
19
13---5/16
(338)
20
(483)
(508)
Upflow Applications on Combustible or Noncombustible Floor-
ing (KGASB subbase not required)
16
(406)
21---5/8
(549)
19
(483)
19
(483)
16---5/8
(422)
22---1/4
(565)
Downflow Applications on Noncombustible Flooring (KGASB
subbase not required)
15---7/8
(403)
16---1/2
(419)
19---5/8
(498)
17–1/2
(445)
Downflow applications on combustible flooring (KGASB sub-
base required)
15---1/8
(384)
16---3/4
(425)
20---5/8
(600)
Downflow Applications on Combustible Flooring with CNPV,
CNRV, CAR, or CAP Coil Assembly or KCAKC coil box
(KGASB subbase not required)
15---1/2
(394)
19
16---1/2
(419)
20
(483)
(508)
Upflow Applications on Combustible or Noncombustible Floor-
ing (KGASB subbase not required)
19---1/2
(495)
21---5/8
(549)
19
(483)
19
(483)
20---1/8
(511)
20
(508)
20---1/4
(514)
22---1/4
(565)
Downflow Applications on Noncombustible Flooring (KGASB
subbase not required)
19---3/8
(492)
19---5/8
(498)
21
(533)
Downflow applications on combustible flooring (KGASB sub-
base required)
18---5/8
(473)
20---5/8
(600)
Downflow Applications on Combustible Flooring with CNPV,
CNRV, CAR, or CAP Coil Assembly or KCAKC coil box
(KGASB subbase not required)
19
19
20
20
(483)
(483)
(508)
(508)
Upflow Applications on Combustible or Noncombustible Floor-
ing (KGASB subbase not required)
23
(584)
21---1/8
(537)
19
(483)
19
(483)
23---5/8
(600)
22---1/4
(565)
Downflow Applications on Noncombustible Flooring (KGASB
subbase not required)
22---7/8
(581)
23---1/2
(597)
19---5/8
(498)
24---1/2
(622)
Downflow applications on Combustible flooring (KGASB sub-
base required)
22---1/8
(562)
23---3/4
(603)
20---5/8
(600)
Downflow Applications on Combustible Flooring with CNPV,
CNRV, CAR, or CAP Coil Assembly or KCAKC coil box
(KGASB subbase not required)
22---1/2
(572)
19
(483)
23---1/2
(597)
20
(508)
W
DOWNFLOW
UPFLO
HORIZONTAL
90û
90û
YES
YES
YES
YES
YES
YES
120û
MIN
120û
MIN
120û
MIN
NOT
NOT
NOT
RECOMMENDED
RECOMMENDED
RECOMMENDED
A02329
Fig. 14 -- Duct Flanges
13
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1
/
4" (6 mm) THREADED ROD
4 REQ.
OUTER DOOR
ASSEMBLY
SECURE ANGLE
IRON TO BOTTOM
OF FURNACE WITH
3 #8 x 3
/4" (19 mm) SCREWS
TYPICAL FOR 2 SUPPORTS
8” (203 mm) MIN FOR
DOOR REMOVAL
1" (25 mm) SQUARE, 11
/4
" x 11 " x 1
/
4
/4
"
(32 x 32 x 6 mm) ANGLE IRON
OR UNI-STRUT MAY BE USED
(2) HEX NUTS, (2) WASHERS & (2) LOCK WASHERS
REQ. PER ROD
A02345
Fig. 15 -- Horizontal Unit Suspension
METHOD 2
USE (4) #8 x 3/4 (19 mm) SHEET
METAL SCREWS FOR EACH
STRAP. THE STRAPS
SHOULD BE VERTICAL
AGAINST THE FURNACE
SIDES AND NOT PULL AWAY
FROM THE FURNACE
SIDES.
METHOD 1
FOLD ALL STRAPS UNDER
FURNACE AND SECURE WTH
(4) #8 x 3/4 (19 mm) SHEET METAL SCREWS
(2 SCREWS IN SIDE AND 2 SCREWS
IN BOTTOM).
A03176
Fig. 16 -- Horizontal Suspension with Straps
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LINE CONTACT ONLY PERMISSIBLE BETWEEN
LINES FORMED BY INTERSECTIONS OF
THE TOP AND TWO SIDES OF THE FURNACE
JACKET AND BUILDING JOISTS,
STUDS, OR FRAMING.
17 3/4
4 3/4
″
(451mm)OVERALL
″
(121mm) UNDER DOOR
1″ (25mm) UNDER FURNACE
GAS
ENTRY
TYPE-B
VENT
EXTEND OUT 12″ (305mm)
FROM FACE OF DOOR
2mm)
(15
*
IN
M
″
6
30-IN. (762mm)
MIN WORK AREA
* WHEN USED WITH
SINGLE WALL VENT
CONNECTIONS
17 3/4
″
(451mm)
SHEET
METAL
22
″
EQUIPMENT MANUAL
SHUT-OFF GAS VALVE
SEDIMENT
TRAP
UNION
A03177
Fig. 17 -- Typical Attic Installation
Not all horizontal furnaces are approved for side return air
connections. (See Fig. 20.)
FILTER ARRANGEMENT
Secure ductwork with proper fasteners for type of ductwork used.
Seal supply-- and return--duct connections to furnace with code
approved tape or duct sealer.
NOTE: Flexible connections should be used between ductwork
and furnace to prevent transmission of vibration.
!
WARNING
Ductwork passing through unconditioned space should be
insulated to enhance system performance. When air conditioning
is used, a vapor barrier is recommended.
Maintain a 1--in. (25 mm) clearance from combustible materials
to supply air ductwork for a distance of 36 in. (914 mm)
horizontally from the furnace. See NFPA 90B or local code for
further requirements.
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal
injury, or death.
Never operate a furnace without a filter or with filter access
door removed.
Ductwork Acoustical Treatment
There are no provisions for an internal filter rack in these
furnaces. An external filter rack is required.
NOTE: Metal duct systems that do not have a 90_ elbow and 10
ft. (3 M) of main duct to the first branch take--off may require
internal acoustical lining. As an alternative, fibrous ductwork may
be used if constructed and installed in accordance with the latest
edition of SMACNA construction standard on fibrous glass
ducts. Both acoustical lining and fibrous ductwork shall comply
with NFPA 90B as tested by UL Standard 181 for Class 1 Rigid
air ducts.
This furnace is shipped with a factory--supplied Media Filter
Cabinet. The Media Filter Cabinet uses either a factory--supplied
standard 3/4--in. (19 mm) filter or 4--in. (102 mm) wide Media
Filter which can be purchased separately.
Refer to the instructions supplied with Media Cabinet for
assembly and installation options.
AIR DUCTS
Supply Air Connections
General Requirements
For a furnace not equipped with a cooling coil, the outlet duct
shall be provided with a removable access panel. This opening
shall be accessible when the furnace is installed and shall be of
such a size that the heat exchanger can be viewed for possible
openings using light assistance or a probe can be inserted for
sampling the air stream. The cover attachment shall prevent leaks.
The duct system should be designed and sized according to
accepted national standards such as those published by: Air
Conditioning Contractors Association (ACCA), Sheet Metal and
Air Conditioning Contractors National Association (SMACNA)
or American Society of Heating, Refrigerating and Air
Conditioning Engineers (ASHRAE) or consult The Air Systems
Design Guidelines reference tables available from your local
distributor. The duct system should be sized to handle the
required system design CFM at the design external static pressure.
The furnace airflow rates are provided in Table 5--Air Delivery
CFM (With Filter).
When a furnace is installed so that the supply ducts carry air
circulated by the furnace to areas outside the space containing the
furnace, the return air shall also be handled by duct(s) sealed to
the furnace casing and terminating outside the space containing
the furnace.
Upflow and Horizontal Furnaces
Connect supply--air duct to flanges on furnace supply--air outlet.
Bend flange upward to 90_ with wide duct pliers. (See Fig. 14.)
The supply--air duct must be connected to ONLY the furnace
supply--outlet--air duct flanges or air conditioning coil casing
(when used). DO NOT cut main furnace casing side to attach
supply air duct, humidifier, or other accessories. All accessories
MUST be connected to duct external to furnace main casing.
15
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Table 5 – Air Delivery -- CFM (With Filter)*
EXTERNAL STATIC PRESSURE (IN. WC)
FURNACE
SIZE
RETURN---AIR
INLET
SPEED
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
High
Me d --- H i g h
Me d --- L o w
Low
1120
1075
1020
960
895
750
650
555
1175
1090
985
895
745
815
680
585
495
1085
1015
920
835
700
720
600
505
405
980
930
835
765
635
605
500
400
305
860
830
740
685
555
455
345
235
--- ---
725
700
620
570
445
340
195
--- ---
045---08 /
024045
Bottom or
Side(s)
930
890
850
805
820
725
1465
1295
1150
1030
860
785
690
1400
1260
1120
1010
835
750
655
700
605
--- ---
High
1325
1210
1085
980
1250
1155
1040
945
560
545
510
345
260
Me d --- H i g h
Medium
Me d --- L o w
Low
045---12/
036045
Bottom or
Side(s)
810
780
High
Me d --- H i g h
Me d --- L o w
Low
1140
915
1105
885
1055
855
1010
825
955
785
655
550
1240
1085
965
845
670
885
725
600
475
1170
1030
925
815
640
815
655
510
415
1090
970
875
770
600
715
530
420
340
1000
890
800
700
540
545
420
325
245
890
785
700
605
460
390
280
--- ---
070---081 /
024070
Bottom or
Side(s)
795
770
740
700
690
665
630
590
--- ---
High
1440
1180
1015
885
1400
1165
1020
885
1355
1150
1010
880
1300
1125
990
865
690
745
645
560
475
345
Me d --- H i g h
Medium
Me d --- L o w
Low
070---12/
036070
Bottom or
Side(s)
695
700
700
High
Me d --- H i g h
Medium
Me d --- L o w
Low
1840
1610
1460
1260
1065
1790
1575
1430
1240
1040
1730
1535
1400
1215
1015
1670
1485
1360
1180
985
1605
1435
1315
1145
955
1530
1370
1260
110
1450
1305
1205
1040
875
1370
1230
1130
985
1275
1145
1055
915
1170
1055
965
070---16/
048070
Bottom or
Side(s)
835
915
825
765
695
High
Me d --- H i g h
Me d --- L o w
Low
1650
1515
1385
1205
2060
1710
1470
1260
1030
1600
1485
1360
1180
2000
1695
1475
1365
1025
1535
1440
1320
1160
1930
1665
1450
1245
1020
1465
1380
1260
1120
1835
1585
1390
1225
990
1385
1300
1195
1065
1755
1480
1335
1165
940
1285
1220
1120
1005
1620
1390
1230
1090
890
1175
1115
1025
925
1055
990
895
830
710
630
1115
955
855
750
615
645
600
565
510
910
775
690
600
500
090---14/
042090
Bottom or
Side(s)
915
810
1490
1245
1120
995
1315
1110
1005
880
High
Me d --- H i g h
Me d --- L o w
Low
090---16/
048090
Bottom or
Side(s)
810
720
High
Me d --- H i g h
Medium
Me d --- L o w
Low
2380
2185
1905
1595
1340
2295
2115
1865
1565
1310
2205
2045
1815
1530
1280
2105
1960
1740
1485
1225
2005
1875
1670
1430
1170
1900
1770
1590
1355
1120
1775
1655
1490
1275
1040
1650
1535
1390
1160
955
1510
1400
1245
1055
850
1335
1240
1110
920
Bottom Only
750
High
Me d --- H i g h
Medium
Me d --- L o w
Low
2485
2175
1845
1540
1280
2415
2130
1815
1515
1250
2330
2070
1770
1475
1220
2230
2000
1720
1435
1190
2135
1930
1655
1385
115
2030
1840
1580
1335
1105
1920
1740
1500
1270
1035
1790
1620
1395
1175
945
1645
1495
1270
1045
845
1485
1345
1090
915
090---20/
060090
Both Side or 1
Side & Bottom
745
High
Me d --- H i g h
Medium
Me d --- L o w
Low
2420
2160
1850
1530
1290
2345
2110
1815
1490
1250
2265
2045
1765
1455
1220
2165
1960
1710
1420
1190
2070
1885
1635
1375
115
1960
1790
1560
1320
1110
1850
1695
1480
1250
1040
1720
1570
1380
1160
950
1570
1445
1250
1055
835
1420
1305
1110
905
1Side Only
740
High
Me d --- H i g h
Me d --- L o w
Low
1625
1510
1360
1195
2055
1750
1545
1300
1050
1575
1470
1335
1180
1990
1725
1525
1290
1045
1515
1415
1295
1155
1910
1670
1490
1275
1015
1445
1355
1250
1115
1815
1605
1445
1235
975
1355
1285
1180
1065
1695
1515
1355
1165
935
1260
1185
1100
980
1575
1400
1260
1085
880
1165
1070
985
990
890
785
725
670
605
1090
975
880
750
610
595
530
475
410
910
785
750
620
515
110---12/
036110
Bottom or
Side(s)
810
860
740
High
1425
1255
1135
1005
815
1230
1120
1020
895
Me d --- H i g h
Medium
Me d --- L o w
Low
110---16/
048110
Bottom or
Side(s)
715
High
Me d --- H i g h
Medium
Me d --- L o w
Low
2530
2225
1895
1565
1320
2460
2190
1885
1555
1295
2380
2135
1865
1535
1265
2285
2075
1820
1505
1235
2200
1995
1770
1465
1205
2085
1910
1700
1410
1160
1970
1805
1610
1350
1105
1835
1695
1520
1265
1035
1695
1565
1410
1175
950
1545
1430
1290
1050
870
Bottom Only
Bottom Sides or
1 Side & Bottom
High
Me d --- H i g h
--- ---
2205
--- ---
2175
2415
2120
2330
2065
2235
1975
2125
1900
1995
1790
1860
1685
1735
1580
1605
1460
110---22/
066110
High
Me d --- H i g h
Medium
Me d --- L o w
Low
2485
2155
1830
1520
1275
2430
2135
1830
1505
1260
2360
2100
1810
1490
1240
2270
2040
1780
1470
1210
2175
1970
1730
1430
1180
2070
1885
1665
1385
1135
1950
1790
1595
1330
1090
1825
1680
1505
1250
1025
1685
1560
1395
1165
930
1535
1420
1275
1055
840
1Side Only
*A filter is required for each return---air inlet. Airflow performance included 3/4---in. (19 mm) washable filter media such as contained in factory ---authorized ac-
cessory filter rack. To determine airflow performance without this filter, assume an additional 0.1 in. wc available external static pressure.
--- --- Indicates unstable operating conditions.
16
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Table 5 -- Air Delivery -- CFM (With Filter)* (Cont.)
EXTERNAL STATIC PRESSURE (IN. WC)
FURNACE
SIZE
RETURN---AIR
INLET
SPEED
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
High
Me d --- H i g h
Me d --- L o w
Low
2090
1790
1545
1325
2010
1755
1525
1320
1930
1705
1500
1295
1835
1640
1450
1265
1710
1550
1380
1210
1590
1465
1315
1150
1470
1360
1215
995
1335
1210
1005
865
1025
945
855
745
835
785
670
540
Bottom
or
Side(s)
135---16/
048135
High
Me d --- H i g h
Me d --- L o w
Low
2485
2195
1880
1640
2400
2150
1850
1635
2310
2090
1820
1615
2215
2000
1780
1585
2110
1920
1715
1530
2000
1825
1635
1465
1880
1720
1540
1370
1725
1565
1415
1255
1535
1405
1290
1150
1355
1255
1160
1040
Bottom
Only
High
Me d --- H i g h
Me d --- L o w
Low
--- ---
--- ---
2385
2060
1820
1615
2305
2010
1780
1585
2195
1945
1715
1530
2085
1865
1635
1465
1960
1765
1540
1370
1825
1660
1415
1255
1670
1515
1290
1150
1465
1325
1160
1040
Bottom Sides
or
1 Side & Bottom
135---22/
066135
2180
1880
1640
2145
1850
1635
High
Me d --- H i g h
Me d --- L o w
Low
High
Me d --- H i g h
Me d --- L o w
Low
2320
2125
1845
1640
2465
2115
1800
1570
2250
2065
1825
1620
2430
2105
1790
1565
2155
1995
1765
1580
2375
2075
1770
1550
2055
1910
1710
1540
2305
2030
1735
1525
1970
1815
1650
1485
2230
1980
1695
1495
1855
1710
1570
1410
2110
1910
1640
1445
1725
1610
1475
1330
2000
1830
1570
1370
1600
1490
1370
1220
1865
1725
1465
1270
1450
1340
1240
1080
1725
1590
1345
1175
1280
1175
1100
960
1545
1425
1225
1070
1 Side Only
Bottom Only
155---20/
060155
Both Sides Or 1
Side & Bottom
High
Me d --- H i g h
--- ---
2155
--- ---
2135
2375
2095
2285
2040
2200
1975
2105
1895
1995
1790
1870
1685
1730
1550
1570
1400
High
Me d --- H i g h
--- ---
2140
--- ---
2095
2260
2040
2180
1975
2085
1890
1975
1810
1865
1705
1740
1595
1605
1480
1455
1325
1 Side Only
*A filter is required for each return---air inlet. Airflow performance included 3/4---in. (19 mm) washable filter media such as contained in factory ---authorized ac-
cessory filter rack. To determine airflow performance without this filter, assume an additional 0.1 in. wc available external static pressure.
--- --- Indicates unstable operating conditions.
NOTE: For horizontal applications, the top--most flange may be
bent past 90_ to allow the evaporator coil to hang on the flange
temporarily while the remaining attachment and sealing of the
coil are performed.
20.) Not all horizontal furnaces are approved for side return air
connections. (See Fig. 20.)
GAS PIPING
Downflow Furnaces
!
WARNING
Connect supply--air duct to supply--air outlet on furnace. Bend
flange inward past 90_ with wide duct pliers. (See Fig. 14.) The
supply--air duct must be connected to ONLY the furnace
supplyoutlet or air conditioning coil casing (when used). When
installed on combustible material, supply--air duct must be
connected to ONLY the accessory subbase, KGASB0201ALL, or
a factory approved air conditioning coil casing. DO NOT cut
main furnace casing to attach supply side air duct, humidifier, or
other accessories. All accessories MUST be connected to duct
external to furnace casing.
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury, death, and/or property damage.
Never purge a gas line into a combustion chamber. Never
test for gas leaks with an open flame. Use a commercially
available soap solution made specifically for the detection
of leaks to check all connections.
Return Air Connections
!
WARNING
!
WARNING
FIRE OR EXPLOSION HAZARD
FIRE HAZARD
Failure to follow this warning could result in personal
injury, death, and/or property damage.
Failure to follow this warning could cause personal injury,
death and/or property damage.
Use proper length of pipe to avoid stress on gas control
manifold and a gas leak.
Never connect return--air ducts to the back of the furnace.
Follow instructions below.
Downflow Furnaces
!
WARNING
The return--air duct must be connected to return--air opening
(bottom inlet) as shown in Fig. 1. DO NOT cut into casing sides
(left or right). Side opening is permitted for only upflow and most
horizontal furnaces. Bypass humidifier connections should be
made at ductwork or coil casing sides exterior to furnace. (See
Fig. 19.)
FIRE OR EXPLOSION HAZARD
Failure to protect gas valve inlet from water and debris
could result in death, personal injury and/or property
damage.
Gas valve inlet and/or inlet pipe must remain capped until
gas supply line is permanently installed to protect the valve
from moisture and debris. Also, install a sediment trap in the
gas supply piping at the inlet to the gas valve.
Upflow and Horizontal Furnaces
The return--air duct must be connected to bottom, sides (left or
right), or a combination of bottom and side(s) of main furnace
casing as shown in Fig. 1. Bypass humidifier may be attached
into unused return air side of the furnace casing. (See Fig. 18 and
17
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A02075
Fig. 18 -- Upflow Return Air Configurations and Restrictions
A02163
Fig. 19 -- Downflow Return Air Configurations and Restrictions
A02162
Fig. 20 -- Horizontal Return Air Configurations and Restrictions
18
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Gas piping must be installed in accordance with national and
local codes. Refer to current edition of NFGC in the U.S. and the
CAN/CSA--B149.1--05 in Canada.
supply connection to furnace and downstream of manual
equipment shutoff valve.
NOTE: The furnace gas control valve inlet pressure tap
connection is suitable to use as test gauge connection providing
test pressure DOES NOT exceed maximum 0.5 psig (14--in. wc)
stated on gas control valve. (See Fig. 53.) Some installations
require gas entry on right side of furnace (as viewed in upflow).
(See Fig. 21.)
Table 6 – Maximum Capacity of Pipe
NOMINAL
IRON PIPE
SIZE
LENGTH OF PIPE --- FT. (M)
INTERNAL
DIA.
IN. (MM)
10
20
30
40
50
(3.0)
(6.0)
(9.1)
(12.1)
(15.2)
IN. (MM)
0.622
(158)
1/2 (12.7)
3/4 (19.0)
1( 25.4)
175
360
120
250
97
200
375
770
1180
82
73
0.824
(20.9)
170
320
660
990
151
285
580
900
1.049
(26.6)
680
465
1-1/4
(31.8)
1-1/2
(38.1)
1.380
(35.0)
1400
2100
950
1.610
(40.9)
1460
2”(51mm)
* Cubic ft. of natural gas per hr for gas pressures of 0.5 psig (14---in. wc)
or less and a pressure drop of 0.5---in. wc (based on a 0.60 specific
gravity gas). Ref: Table 6.2 ANSI Z223---2006/NFPA 54---2006.
Street Elbow
Installations must be made in accordance with all authorities
having jurisdiction. If possible, the gas supply line should be a
separate line running directly from meter to furnace.
A08551
Fig. 21 -- Burner and Manifold
NOTE: In the state of Massachusetts:
Install a sediment trap in riser leading to furnace as shown in Fig.
22. Connect a capped nipple into lower end of tee. Capped nipple
should extend below level of furnace gas controls. Place a ground
joint union between furnace gas control valve manifold and
exterior manual equipment gas shutoff valve.
1. Gas supply connections MUST be performed by a li-
censed plumber or gas fitter.
2. When flexible connectors are used, the maximum length
shall not exceed 36 inches (915 mm).
3. When lever handle type manual equipment shutoff valves
are used, they shall be T--handle valves.
GAS
SUPPLY
4. The use of copper tubing for gas piping is NOT approved
by the state of Massachusetts.
MANUAL
SHUTOFF
VALVE
Refer to Table 6 for recommended gas pipe sizing. Risers must be
used to connect to furnace and to meter. Support all gas piping
with appropriate straps, hangers, etc. Use a minimum of 1 hanger
every 6 ft. (1.8 M). Joint compound (pipe dope) should be
applied sparingly and only to male threads of joints. Pipe dope
must be resistant to the action of propane gas.
(REQUIRED)
SEDIMENT
TRAP
UNION
!
WARNING
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury, death, and/or property damage.
If local codes allow the use of a flexible gas appliance
connector, always use a new listed connector. Do not use a
connector which has previously served another gas
appliance. Black iron pipe shall be installed at the furnace
gas control valve and extend a minimum of 2 in. (51 mm)
outside the furnace.
A02035
Fig. 22 -- Typical Gas Pipe Arrangement
!
CAUTION
FURNACE DAMAGE HAZARD
Failure to follow this caution may result in furnace damage.
Connect gas pipe to furnace using a backup wrench to
avoid damaging gas controls and burner misalignment.
An accessible manual equipment shutoff valve MUST be
installed external to furnace casing and within 6 ft. of furnace. A
1/8--in. (3 mm) NPT plugged tapping, accessible for test gauge
connection, MUST be installed immediately upstream of gas
19
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FIELD 24-VOLT WIRING
FIELD 115-, 208/230-, 460-VOLT WIRING
FACTORY 24-VOLT WIRING
FACTORY 115-VOLT WIRING
NOTE 2
1-STAGE
THERMOSTAT
TERMINALS
W
C
Y
R
G
FIVE
WIRE
FIELD-SUPPLIED
FUSED DISCONNECT
THREE-WIRE
HEATING-
ONLY
208/230- OR
460-VOLT
THREE
PHASE
W2
BLK
BLK
COM
W/W1
WHT
WHT
208/230-
VOLT
SINGLE
PHASE
GND
NOTE 1
Y/Y2
115-VOLT FIELD- JUNCTION
SUPPLIED
FUSED
BOX
R
G
GND
CONTROL
BOX
CONDENSING
UNIT
DISCONNECT
24-VOLT
TERMINAL
BLOCK
NOTES: 1. Connect Y/Y2-terminal as shown for proper operation.
2. Some thermostats require a "C" terminal connection as shown.
3. If any of the original wire, as supplied, must be replaced, use
same type or equivalent wire.
FURNACE
A95236
Fig. 23 -- Field Wiring Diagram
A 1/8--in. (3 mm) NPT plugged tapping, accessible for test gauge
connection, MUST be installed immediately upstream of gas
supply connection to furnace and downstream of manual
equipment shutoff valve.
!
WARNING
ELECTRICAL SHOCK AND FIRE HAZARD
Piping should be pressure and leak tested in accordance with
NFGC in the United States or CAN/CSA--B149.1--05 in Canada,
local, and national plumbing and gas codes before the furnace has
been connected. After all connections have been made, purge
lines and check for leakage at furnace prior to operating furnace.
If pressure exceeds 0.5 psig (14--in. wc), gas supply pipe must be
disconnected from furnace and capped before and during supply
pipe pressure test. If test pressure is equal to or less than 0.5 psig
(14--in. wc), turn off electric shutoff switch located on furnace gas
control valve and accessible manual equipment shutoff valve
before and during supply pipe pressure test. After all connections
have been made, purge lines and check for leakage at furnace
prior to operating furnace.
Failure to follow this warning could result in personal
injury, death, or property damage.
The cabinet MUST have an uninterrupted or unbroken
ground according to NEC ANSI/NFPA 70--2008 and
Canadian Electrical Code CSA C22.1 or local codes to
minimize personal injury if an electrical fault should occur.
This may consist of electrical wire, conduit approved for
electrical ground or a listed, grounded power cord (where
permitted by local code) when installed in accordance with
existing electrical codes. Refer to the power cord
manufacturer’s ratings for proper wire gauge. Do not use
gas piping as an electrical ground.
The gas supply pressure shall be within the maximum and
minimum inlet supply pressures marked on the rating plate with
the furnace burners ON and OFF.
!
CAUTION
ELECTRICAL CONNECTIONS
FURNACE MAY NOT OPERATE HAZARD
!
WARNING
Failure to follow this caution may result in intermittent
furnace operation.
ELECTRICAL SHOCK HAZARD
Furnace control must be grounded for proper operation or
else control will lock out. Control must remain grounded
through green/yellow wire routed to gas valve and manifold
bracket screw.
Failure to follow this warning could result in personal
injury or death.
Blower access panel door switch opens 115--v power to
control. No component operation can occur. Do not bypass
or close switch with panel removed.
115--V WIRING
Verify that the voltage, frequency, and phase correspond to that
specified on unit rating plate. Also, check to be sure that service
provided by utility is sufficient to handle load imposed by this
equipment. Refer to rating plate or Table 7 for equipment
electrical specifications.
See Fig. 23 for field wiring diagram showing typical field 115--v
wiring. Check all factory and field electrical connections for
tightness.
Field--supplied wiring shall conform with the limitations of 63_F
(33_C) rise.
20
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Table 7 – Electrical Data
MAXIMUM
WIRE
MAXIMUM
OPERATING VOLTAGE
RANGE
V O LT S ---
H E R T Z ---
PHASE
MAX
UNIT
MINIMUM
WIRE
FUSE OR
FURNACE
UNIT
L E N G T H ---
FT. (M)‡
49 (14.9)
38 (11.5)
51 (15.5)
37 (11.2)
27 (8.2)
CKT BKR
AMPS†
15
SIZE
AMPACITY#
AMPS
GAUGE
MAX*
MIN.*
1 1 5 --- 6 0 --- 1
1 1 5 --- 6 0 --- 1
1 1 5 --- 6 0 --- 1
1 1 5 --- 6 0 --- 1
1 1 5 --- 6 0 --- 1
1 1 5 --- 6 0 --- 1
1 1 5 --- 6 0 --- 1
1 1 5 --- 6 0 --- 1
1 1 5 --- 6 0 --- 1
1 1 5 --- 6 0 --- 1
1 1 5 --- 6 0 --- 1
1 1 5 --- 6 0 --- 1
1 1 5 --- 6 0 --- 1
1 1 5 --- 6 0 --- 1
127
127
127
127
127
127
127
127
127
127
127
127
127
127
104
104
104
104
104
104
104
104
104
104
104
104
104
104
5.3
7.1
5.2
7.3
10.1
8.2
9.9
12.9
8.2
10.1
13.7
10.2
14.5
15.0
045---08/024045
045---12/036045
070---08/024070
070---12/036070
070---16/048070
090---14/042090
090---16/048090
090---20/060090
110---12/036110
110---16/048110
110---22/066110
135---16/048135
135---22/066135
155---20/060155
7.42
9.67
7.22
14
14
14
14
14
14
14
12
14
14
12
14
12
12
15
15
15
15
15
15
20
15
15
20
15
20
9.90
13.42
10.84
13.0
16.70
10.76
13.19
17.60
13.28
18.61
19.34
34 (10.3)
28 (8.5)
34 (10.3)
34 (10.3)
28 (8.5)
32 (9.7)
27 (8.2)
30 (9.1)
29 (8.8)
20
* Permissible limits of the voltage range at which the unit operates satisfactorily.
# Unit ampacity = 125% of largest operating component’s full load amps plus 100% of all other potential operating components (EAC, humidifier,
etc.) full load amps.
{ Time---delay type is recommended.
} Length shown is as measured 1 way along wire path between unit and service panel for maximum 2% voltage drop.
U.S. Installations: Make all electrical connections in accordance
with National Electrical Code (NEC) ANSI/NFPA 70--2008 and
any local codes or ordinances that might apply.
4. Fasten J--Box to casing with the two screws removed in
Step 1.
5. Route J--Box wires within furnace away from sharp edges,
rotating parts, and hot surfaces.
Canadian Installations: Make all electrical connections in
accordance with Canadian Electrical Code CSA C22.1 or
authorities having jurisdiction.
!
WARNING
FIRE HAZARD
TWO
Failure to follow this warning could result in personal
injury, death, or property damage.
Do not connect aluminum wire between disconnect switch
and furnace. Use only copper wire.
Use a separate branch electrical circuit with a properly sized fuse
or circuit breaker for this furnace. See Table 7 for wire size and
fuse specifications. A readily accessible means of electrical
disconnect must be located within sight of the furnace.
NOTE: Proper polarity must be maintained for 115--v wiring. If
polarity is incorrect, control LED status indicator light will flash
rapidly and furnace will NOT operate.
A02099
Fig. 24 -- Relocating J--Box
J--BOX RELOCATION
ELECTRICAL CONNECTION TO J--BOX
NOTE: If factory location of J--Box is acceptable, go to next
section (ELECTRICAL CONNECTION TO J--BOX).
Field--Supplied Electrical Box on Furnace J--Box Bracket. See
Fig. 26.
NOTE: On 14” wide casing models, the J--Box shall not be
relocated to other side of furnace casing when the vent pipe is
routed within the casing.
1. Remove cover from furnace J--Box.
2. Attach electrical box to furnace J--Box bracket with at least
two field--supplied screws through holes in electrical box
into holes in bracket. Use blunt--nose screws that will not
pierce wire insulation.
1. Remove and save two screws holding J--Box. (See Fig.
24.)
NOTE: The J--Box cover need not be removed from the J--Box
in order to move the J--Box. Do NOT remove green ground
screw inside J--Box. The ground screw is not threaded into the
casing flange and can be lifted out of the clearance hole in casing
while swinging the front edge of the J--box outboard of the
casing.
3. Route furnace power wires through holes in electrical box
and J--Box bracket, and make field--wire connections in
electrical box. Use best practices (NEC in U.S. and CSA
C22.1 in Canada) for wire bushings, strain relief, etc.
4. Route and secure field ground wire to green ground screw
on J--Box bracket.
2. Cut wire tie on loop in furnace wires attached to J--Box.
3. Move J--Box to desired location.
5. Connect line voltage leads as shown in Fig. 23.
21
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6. Reinstall cover to J--Box. Do not pinch wires between
cover and bracket.
Electrical Box on Furnace Casing Side. See Fig. 25.
11. Secure field ground wire to J--Box green ground screw.
12. Complete electrical box wiring and installation. Connect
line voltage leads as shown in Fig. 23. Use best practices
(NEC in U.S. and CSA C22.1 in Canada) for wire bush-
ings, strain relief, etc.
13. Reinstall cover to J--Box. Do not pinch wires between
cover and bracket.
!
WARNING
FIRE OR ELECTRICAL SHOCK HAZARD
POWER CORD INSTALLATION IN FURNACE J--BOX
Failure to follow this warning could result in personal
injury, death, or property damage.
NOTE: Power cords must be able to handle the electrical
requirements listed in Table 7. Refer to power cord
manufacturer’s listings.
If field--supplied manual disconnect switch is to be mounted
on furnace casing side, select a location where a drill or
fastener cannot damage electrical or gas components.
1. Remove cover from J--Box.
2. Route listed power cord through 7/8--inch (22 mm) dia-
meter hole in J--Box.
3. Secure power cord to J--Box bracket with a strain relief
bushing or a connector approved for the type of cord used.
4. Secure field ground wire to green ground screw on J--Box
bracket.
5. Connect line voltage leads as shown in Fig. 23.
6. Reinstall cover to J--Box. Do not pinch wires between
cover and bracket.
BX. CABLE INSTALLATION IN FURNACE J--BOX
1. Remove cover from J--Box.
2. Route BX cable into 7/8--inch (22 mm) diameter hole in
J--Box.
3. Secure BX cable to J--Box bracket with connectors ap-
proved for the type of cable used.
4. Secure field ground wire to green ground screw on J--Box
bracket.
5. Connect line voltage leads as shown in Fig. 23.
6. Reinstall cover to J--Box. Do not pinch wires between
cover and bracket.
24--V WIRING
Make field 24--v connections at the 24--v terminal strip. (See Fig.
33.) Connect terminal Y/Y2 as shown in Fig. 26--32 for proper
cooling operation. Use only AWG No. 18, color--coded, copper
thermostat wire.
A03221
The 24--v circuit contains an automotive--type, 3--amp. fuse
located on the control. Any direct shorts during installation,
service, or maintenance could cause this fuse to blow. If fuse
replacement is required, use ONLY a 3--amp. fuse of identical
size.
Fig. 25 -- Field--Supplied Electrical Box on Furnace Casing
1. Select and remove a hole knockout in the casing where the
electrical box is to be installed.
NOTE: Check that duct on side of furnace will not interfere with
installed electrical box.
2. Remove the desired electrical box hole knockout and posi-
tion the hole in the electrical box over the hole in the fur-
nace casing.
3. Fasten the electrical box to casing by driving two field--
supplied screws from inside electrical box into casing
steel.
4. Remove and save two screws holding J--Box. (See Fig.
24.)
5. Pull furnace power wires out of 1/2--inch (12 mm) diamet-
er hole in J--Box. Do not loosen wires from strain--relief
wire--tie on outside of J--Box.
6. Route furnace power wires through holes in casing and
electrical box and into electrical box.
7. Pull field power wires into electrical box.
8. Remove cover from furnace J--Box.
9. Route field ground wire through holes in electrical box
and casing, and into furnace J--Box.
10. Reattach furnace J--Box to furnace casing with screws re-
moved in Step 4.
22
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See notes 2, 5, 8, 10, 11 and 12
on the page following these figures
See notes 1, 2, 3, 4, 6, 8, 9, 10, 12, 13 and 15
on the page following these figures
A03179
A03178
Fig. 26 -- Two--Stage Furnace with Two--Speed Air
Conditioner
Fig. 28 -- Two--Stage Furnace with Two--Speed Heat Pump
(Dual Fuel)
See notes 1, 2, 4, 11, 14, 15, and 16
on the page following these figures
See notes 1, 2, 4, 6, 7, 9, 10, 11, and 15
on the page following these figures
A03180
A03181
Fig. 27 -- Two--Stage Furnace with Single--Speed Heat Pump
(Dual Fuel)
Fig. 29 -- Dual Fuel Thermostat with Two--Stage Furnace
and Single--Speed Heat Pump
23
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7
See notes 2, 11, and 12 on the
page following these figures
See notes 1, 2, 3, 4, 12, 13, 14, 15, and 17
on the page following these figures
A03182
A03183
Fig. 30 -- Dual Fuel Thermostat with Two--Stage Furnace
and Two--Speed Heat Pump
Fig. 31 -- Two--Stage Thermostat with Two--Stage Furnace
and Two--Speed Air Conditioner
See notes 1 and 2 on the page
following these figures
A03184
Fig. 32 -- Single--Stage Thermostat with Two--Stage Furnace and Two--Speed Air Conditioner
NOTES: For Figu r es 26 --- 32
1. Heat pump MUST have a high pressure switch for dual fuel applications.
2. Refer to outdoor equipment Installation Instructions for additional information and setup procedure.
3. Outdoor Air Temperature Sensor must be attached in all dual fuel applications.
4. Dip switch No. 1 on Thermidistat should be set in OFF position for air conditioner installations. This is factory default.
5. Dip switch No. 1 on Thermidistat should be set in ON position for heat pump installations.
6. Dip switch No. 2 on Thermidistat should be set in OFF position for single---speed compressor operation. This is factory default.
7. Dip switch No. 2 on Thermidistat should be set in ON position for two---speed compressor operation.
8. Configuration Option No. 10 “Dual Fuel Selection” must be turned ON in all dual fuel applications.
9. NO connection should be made to the furnace HUM terminal when using a Thermidistat.
10. Optional connection: If wire is connected, dip switch SW1---2 on furnace control should be set in ON position to allow Thermidistat/Thermostat to control
furnace staging.
11. Optional connection: If wire is connected, ACRDJ jumper on furnace control should be removed to allow Thermidistat/Thermostat to control outdoor unit
staging.
12. When using both a two---stage furnace and a two---stage heat pump, the furnace must control its own high---stage heating operation via furnace control
algorithm.
13. The RVS Sensing terminal “L” should not be connected. This is internally used to sense defrost operation.
14. DO NOT SELECT the “FURNACE INTERFACE” or “BALANCE POINT” option on the two---speed heat pump control board. This is controlled internally by
the Thermidistat/Dual Fuel Thermostat.
15. Dip switch D on Dual Fuel Thermostat should be set in OFF position for single---speed compressor operation. This is factory default.
16. Dip switch D on Dual Fuel Thermostat should be set in ON position for two---speed compressor operation.
24
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ACCESSORIES
NOTE: DO NOT connect furnace control HUM terminal to
HUM (humidifier) terminal on Thermidistat, Zone Controller or
similar device. See Thermidistatt, Zone Controller, thermostat,
or controller manufacturer’s instructions for proper connection.
1. Electronic Air Cleaner (EAC)
Connect an accessory Electronic Air Cleaner (if used) us-
ing 1/4--in female quick connect terminals to the two male
1/4--in quick--connect terminals on the control board
marked EAC--1 and EAC--2. The terminals are rated for
115VAC, 1.0 amps maximum and are energized during
blower motor operation. (See Fig. 33.)
VENTING
The furnace shall be connected to a listed factory built chimney
or vent or a clay--tile lined masonry or concrete chimney. Venting
into an unlined masonry chimney or concrete chimney is
prohibited. When an existing Category I furnace is removed or
replaced, the original venting system may no longer be sized to
properly vent the attached appliances. An improperly sized
Category I venting system could cause the formation of
condensate in the furnace and vent, leakage of condensate and
combustion products, and spillage of combustion products into
the living space.
2. Humidifier (HUM)
Connect an accessory 24 VAC, 0.5 amp. maximum hu-
midifier (if used) to the 1/4--in male quick--connect HUM
terminal and COM--24V screw terminal on the control
board thermostat strip. The HUM terminal is energized
when gas valve relay (GVR) is energized. (See Fig. 33.)
NOTE: A field--supplied, 115--v controlled relay connected to
EAC terminals may be added if humidifier operation is desired
during blower operation.
SETUP SWITCHES
LOW-HEAT ONLY AND
BLOWER OFF-DELAY
TWINNING AND/OR
COMPONENT TEST
TERMINAL
ACRDJ - AIR CONDITIONING
RELAY DISABLE JUMPER
LHT
OFF
DLY
24-V-THERMOSTAT
TERMINALS
TEST/TWIN
TRANSFORMER 24-VAC
HUM
CONNECTIONS
0.5-AMP024 VAC
HUMIDIFIER TERMINAL
(24-VAC 0.5 AMP MAX.)
FUSE 3-AMP
AT
PL1 - LOW VOLTAGE MAIN
HARNESS CONNECTOR
S
SEC-1
SEC-2
U
D
3-AMP FUSE
S
E
C
L
O
E
D
LED OPERATION &
DIAGNOSTIC LIGHT
EAC-2
NEUTRAL-L2
PL3
BLW
BHI/LOR
115-VAC (L2) NEUTRAL
CONNECTIONS
BHT/CLR
BLWR
HI HEAT
LO HEAT
COOL
SPARE-2
1-AMP@115 VAC
EAC-1
SPARE-1
PR-1
HSI HI LO
SPARE-1
SPARE-2
PL2 - HOT SURFACE
IGNITER & INDUCER
MOTOR CONNECTOR
115-VAC (L1) LINE
VOLTAGE CONNECTION
COOL
BLOWER SPEED
SELECTION TERMINALS
EAC-1 TERMINAL
(115-VAC 1.0 AMP MAX.)
A02017
Fig. 33 -- Furnace Control--PSC Blower Motor
25
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CAN/CSA--B149.1--05, local building codes, and furnace and
vent manufacturers’ instructions.
The following information and warning must be considered in
addition to the requirements defined in the NFGC or the
CAN/CSA--B149.1--05.
!
WARNING
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal
injury or death.
!
Failure to follow the steps outlined below for each
appliance connected to the venting system being placed into
operation could result in carbon monoxide poisoning or
death. The following steps shall be followed for each
appliance connected to the venting system being placed into
operation, while all other appliances connected to the
venting system are not in operation:
WARNING
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal
injury or death.
Do not bypass the draft safeguard switch, as an unsafe
condition could exist which must be corrected.
1. Seal any unused openings in venting system.
2. Inspect the venting system for proper size and
horizontal pitch, as required in the National Fuel Gas Code,
ANSI Z223.1/NFPA 54 or the CSA B149.1, Natural Gas
and Propane Installation Code and these instructions.
Determine that there is no blockage or restriction, leakage,
corrosion and other deficiencies, which could cause an
unsafe condition.
3. As far as practical, close all building doors and windows
and all doors between the space in which the appliance(s)
connected to the venting system are located and other
spaces of the building.
1. If a vent (common or dedicated) becomes blocked, the fur-
nace will be shut off by the draft safeguard switch located
on the vent elbow.
2. Two--stage furnaces require Type B vent connectors out-
side the casing in all configurations. Single wall vent con-
nector may be used inside the furnace casing with the
transition to Type B vent outside the furnace casing. Size
the connector so that the FAN--Min vent connector capa-
city is equal to or lower than the low fire rate of the fur-
nace and the FAN--Max vent connector capacity is equal
to or higher than the furnace high fire rate.
4. Close fireplace dampers.
5. Turn on clothes dryers and any appliance not connected
to the venting system. Turn on any exhaust fans, such as
range hoods and bathroom exhausts, so they are operating
at maximum speed. Do not operate a summer exhaust fan.
6. Follow the lighting instructions. Place the appliance
being inspected into operation. Adjust the thermostat so
appliance is operating continuously.
7. Test for spillage from draft hood equipped appliances at
the draft hood relief opening after 5 minutes of main burner
operation. Use the flame of a match or candle.
8. If improper venting is observed during any of the above
tests, the venting system must be corrected in accordance
with the National Fuel Gas Code, ANSI Z223.1/NFPA 54
and/or CSA B149.1, Natural Gas and Propane Installation
Code.
9. After it has been determined that each appliance
connected to the venting system properly vents when tested
as outlined above, return doors, windows, exhaust fans,
fireplace dampers and any other gas--fired burning
appliance to their previous conditions of use.
3. Do not vent this Category I furnace into a single wall ded-
icated or common vent. The dedicated or common vent is
considered to be the vertical portion of the vent system
that terminates outdoors.
4. Vent connectors serving Category I furnaces shall not be
connected into any portion of a mechanical draft system
operating under positive pressure.
5. In the US: Do not vent this appliance with any solid fuel
burning appliance. In Canada: Check with the authority
having jurisdiction for approval on use with solid fuel
burning appliance.
6. Category I furnaces must be vented vertically or nearly
vertically unless equipped with a listed mechanical venter.
See the SIDEWALL VENTING section.
7. Do not vent this appliance into an unlined masonry chim-
ney. Refer to Chimney Inspection Chart, Fig. 34.
MASONRY CHIMNEY REQUIREMENTS
NOTE: These furnaces are CSA design--certified for use in
exterior tile--lined masonry chimneys with a factory accessory
Chimney Adapter Kit. Refer to the furnace rating plate for correct
kit usage. The Chimney Adapter Kits are for use with ONLY
furnaces having a Chimney Adapter Kit number marked on the
furnace rating plate.
Vent system or vent connectors may need to be resized. Vent
systems or vent connectors must be sized to approach minimum
size as determined using appropriate table found in the NFGC or
CAN/CSA--B149.1--05.
If a clay tile--lined masonry chimney is being used and it is
exposed to the outdoors below the roof line, relining might be
required. Chimneys shall conform to the Standard for Chimneys,
Fireplaces, Vents, and Solid Fuel Burning Appliances
ANSI/NFPA 211--2006 in the United States and to a Provincial or
Territorial Building Code in Canada (in its absence, the National
Building Code of Canada) and must be in good condition.
GENERAL VENTING REQUIREMENTS
Follow all safety codes for proper vent sizing and installation
requirements, including local building codes, the National Fuel
Gas Code ANSI Z223.1--2006/NFPA 54--2006 (NFGC), Parts 12
and 13 in the United States or the National Standard of Canada,
Natural Gas and Propane Installation Code CSA--B149.1--05
(CAN/CSA--B149.1--05), Section 8 and Appendix C in Canada,
the local building codes, and furnace and vent manufacturers’
instructions.
U.S.A.--Refer to Sections 13.1.8 and 13.2.20 of the NFPA 54 /
ANSI Z223.1--2006 or the authority having jurisdiction to
determine whether relining is required. If relining is required, use
a properly sized listed metal liner, Type--B vent, or a listed
alternative venting design.
These furnaces are design--certified as Category I furnaces in
accordance with ANSI Z21.47--2006/CSA 2.3--2006 and operate
with a non--positive vent static pressure to minimize the potential
for vent gas leakage. Category I furnaces operate with a flue loss
not less than 17% to minimize the potential for condensation in
the venting system. These furnaces are approved for common
venting and multi--story venting with other fan assisted or draft
hood equipped appliances in accordance with the NFCG or the
NOTE: See the NFPA 54 / ANSI Z223.1--2006, 13.1.8 and
13.2.20 regarding alternative venting design and the exception,
which cover installations such as the Chimney Adapter Kits
KGACA02014FC and KGACA02015FC, which are listed for
use with these furnaces.
26
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CHIMNEY INSPECTION CHART
For additional requirements refer to the National Fuel Gas Code NFPA 54/ANSI Z223.1 and ANSI/NFPA 211
Chimneys, Fireplaces, Vents, and Solid Fuel Burning Appliances in the U.S.A. or to the Canadian
installation Code CSA-B149.1 in Canada.
Crown
Rebuild
crown.
condition:
Missing mortar
or brick?
Yes
No
Is chimney
property lined with
clay tile liner?
No
Yes
Repair
Is
Reline
No
liner or top seal
or reline chimney as
necessary.
liner and top
seal in good
condition?
Repair
Yes
Debris
Mortar
or tile
debris?
in cleanout?
Yes
Yes
Remove mortar
and tile debris
Mortar, tile, metal vent,
fuel oil residue?
No
Remove metal vent
or liner.
No
Clay
Yes
tile misalignment,
missing sections,
gaps?
Consult
Part B of
Not Suitable
chimney adapter venting
instructions for
application
No
No
suitability.
Is chimney
lined with properly
sized, listed liner or
Type-B vent?
Line chimney with property
sized, listed flexible metal
liner or Type-B vent per
NFGC or NSCNGPIC Vent
Sizing Tables and liner or
vent manufacturer’s
Condensate
drainage at bottom
of chimney?
Suitable
Yes
Yes
Install chimney
adapter per
instructions.
No
Installation instructions.
Not Suitable
Consult
Yes
Chimney
exposed to
outdoors below
roof line?
Part C of
chimney adapter venting
instructions for
application
Is chimney
to be dedicated to
a single
No
Suitable
Yes
furnace?
suitability
Install chimney
adapter per
instructions.
No
Chimney is
acceptable for use.
A03206
Fig. 34 -- Chimney Inspection Chart
27
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The Chimney Adapter Kit is a listed alternative venting system
for these furnaces. See the kit instructions for complete details.
Table 9 – Minimum Allowable Input Rating of Space--Heat-
ing Appliance in Thousands of BTUH per Hour
Canada (and U.S.A.)--This furnace is permitted to be vented into
a clay tile--lined masonry chimney that is exposed to the outdoors
below the roof line, provided:
INTERNAL AREA OF CHIMNEY
SQ. IN. (SQ. MM)
VENT HEIGHT
1. Vent connector is Type--B double--wall, and
(FT)
12
(7741)
19
28
38
2. This furnace is common vented with at least 1 draft hood--
equipped appliance, and
3. The combined appliance input rating is less than the max-
imum capacity given in Table 8, and
(12258) (18064) (24516)
Local 99% Winter Design
Temperature: 17 to 26_F ( --- 8 t o --- 3 _C)
6 (1.8)
8 (2.4)
0
55
74
99
141
154
169
212
258
362
4. The input rating of each space heating appliance is greater
than the minimum input rating given in Table 9 for the
local 99% Winter Design Temperature. Chimneys having
52
111
125
167
212
NR
10 (3.0)
15 (4.6)
20 (6.1)
30 (9.1)
NR
NR
NR
NR
90
2
2)
NR
NR
NR
internal areas greater than 38 in (24516 mm require fur-
nace input ratings greater than the input ratings of these
furnaces. See footnote at bottom of Table 9, and
5. The authority having jurisdiction approves.
Local 99% Winter Design
Temperature: 5 to 16_F * ( --- 1 5 t o --- 9 _C)
If all of these conditions cannot be met, an alternative venting
design shall be used, such as the listed chimney adapter kit with a
furnace listed for use with the kit, a listed chimney--lining system,
or a Type--B common vent.
Inspections before the sale and at the time of installation will
determine the acceptability of the chimney or the need for repair
and/or (re)lining. Refer to Fig. 34 to perform a chimney
inspection. If the inspection of a previously used tile--lined
chimney:
6 (1.8)
8 (2.4)
NR
NR
NR
NR
NR
NR
78
94
121
135
149
193
NR
166
182
198
247
293
377
10 (3.0)
15 (4.6)
20 (6.1)
30 (9.1)
111
NR
NR
NR
NR
Local 99% Winter Design
Temperature: ---10 to 4_F * ( --- 2 3 t o --- 1 6 _C)
a. Shows signs of vent gas condensation, the chimney
should be relined in accordance with local codes and the
authority having jurisdiction. The chimney should be re-
lined with a listed metal liner, Type--B vent, or a listed
chimney adapter kit shall be usedto reducecondensation.
If a condensate drain is required by local code, refer to
the NFPA 54 / ANSI Z223.1--2006, Section 12.10 for ad-
ditional information on condensate drains.
6 (1.8)
8 (2.4)
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
145
159
175
NR
NR
NR
196
213
231
283
333
NR
10 (3.0)
15 (4.6)
20 (6.1)
30 (9.1)
Local 99% Winter Design
b. Indicates the chimney exceeds the maximum permissible
size in the tables, the chimney should be rebuilt or relined
to conform to the requirements of the equipment being
installed and the authority having jurisdiction.
Temperature: ---11_F ( --- 2 4 _C) or lower
Not recommended for any vent configuration.
*The 99.6% heating db temperatures found in the 1997 or 2001 ASHRAE
Fundamentals Handbook, Climatic Design Information chapter, Table 1A
(United States) and 2A (Canada) or the 2005 ASHRAE Fundamentals
handbook, Climatic Design Information chapter, and the CD---ROM in-
cluded with the 2005 ASHRAE Fundamentals Handbook.
A chimney without a clay tile liner, which is otherwise in good
condition, shall be rebuilt to conform to ANSI/NFPA 211 or be
lined with a UL listed (ULC listed in Canada) metal liner or UL
listed Type--B vent. Relining with a listed metal liner or Type--B
vent is considered to be a vent--in--a--chase.
APPLIANCE APPLICATION REQUIREMENTS
Appliance operation has a significant impact on the performance
of the venting system. If the appliances are sized, installed,
adjusted, and operated properly, the venting system and/or the
appliances should not suffer from condensation and corrosion.
The venting system and all appliances shall be installed in
accordance with applicable listings, standards, and codes.
If a metal liner or Type--B vent is used to line a chimney, no other
appliance shall be vented into the annular space between the
chimney and the metal liner.
Exterior Masonry Chimney FAN + NAT
Installations with Type--B Double--Wall Vent
Connectors ENFPA & AGA
The furnace should be sized to provide 100% of the design
heating load requirement plus any margin that occurs because of
furnace model size capacity increments. Heating load estimates
can be made using approved methods available from Air
Conditioning Contractors of America (Manual J); American
Society of Heating, Refrigerating, and Air--Conditioning
Engineers; or other approved engineering methods. Excessive
over--sizing of the furnace could cause the furnace and/or vent to
fail prematurely. When a metal vent or metal liner is used, the
vent must be in good condition and be installed in accordance
with the vent manufacturer’s instructions.
Table 8 – Combined Appliance Maximum Input Rating in
Thousands of BTUH per Hour
INTERNAL AREA OF CHIMNEY
SQ. IN. (SQ. MM)
VENT HEIGHT
FT. (M)
12
19
(12258)
28
(18064)
38
(24516)
(7741)
6 (1.8)
8 (2.4)
10 (3.)
15 (4.5)
20 (6.0)
30 (9.1)
74
80
84
NR
NR
NR
119
130
138
152
NR
178
193
207
233
250
NR
257
279
299
334
368
404
To prevent condensation in the furnace and vent system, the
following precautions must be observed:
NR
1. The return--air temperature must be at least 60_F (15_C)
db except for brief periods of time during warm--up from
setback at no lower than 55_F (13_C) db or during initial
start--up from a standby condition.
28
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2. Adjust the gas input rate per the installation instructions.
Low gas input rate causes low vent gas temperatures, caus-
ing condensation and corrosion in the furnace and/or vent-
ing system. Derating is permitted only for altitudes above
2000 ft
3. Adjust the air temperature rise to the midpoint of the rise
range or slightly above. Low air temperature rise can cause
low vent gas temperature and potential for condensation
problems.
4. Set the thermostat heat anticipator or cycle rate to reduce
short cycling.
Air for combustion must not be contaminated by halogen
compounds which include chlorides, fluorides, bromides, and
iodides. These compounds are found in many common home
products such as detergent, paint, glue, aerosol spray, bleach,
cleaning solvent, salt, and air freshener, and can cause corrosion
of furnaces and vents. Avoid using such products in the
combustion--air supply. Furnace use during construction of the
building could cause the furnace to be exposed to halogen
compounds, causing premature failure of the furnace or venting
system due to corrosion.
SEE NOTES: 1,2,4,7,8,9
on the page following
these figures
Vent dampers on any appliance connected to the common vent
can cause condensation and corrosion in the venting system. Do
not use vent dampers on appliances common vented with this
furnace.
A03208
Fig. 35 -- Upflow Application--Vent Elbow Up
ADDITIONAL VENTING REQUIREMENTS
A 4 in. (102 mm) round vent elbow is supplied with the furnace.
A 5 in. or 6 in. (127 or 152 mm) vent connector may be required
for some model furnaces. A field--supplied 4 in. to 5 in. (102 to
127 mm) or 4 in. to 6 in. (102 mm to 152 mm) sheet metal
increaser fitting is required when 5 in. or 6 in. (127 or 152 mm)
vent connector is used. See Fig. 35--47 Venting Orientation for
approved vent configurations.
See Venting Notes after Fig. 47.
SEE NOTES: 1,2,3,4,7,8,9
on the pages following
these figures
A03209
Fig. 36 -- Upflow Application--Vent Elbow Right
29
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SEE NOTES:1,2,3,4,5,7,8,9
on the page following
these figures
SEE NOTES: 1,2,4,5,6,7,8,9,10
on the page following these figures
A03210
A03207
Fig. 37 -- Downflow Application--Vent Elbow Up then Left
Fig. 39 -- Downflow Application--Vent Elbow Left then Up
SEE NOTES: 1,2,4,5,7,8,9
on the page following
these figures
SEE NOTES:1,2,3,4,5,7,8,9
on the page following
these figures.
A03211
A03212
Fig. 38 -- Downflow Application--Vent Elbow Up
Fig. 40 -- Downflow Application--Vent Elbow Up then Right
30
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SEE NOTES: 1,2,4,5,7,8,9 on the page
following these figures
SEE NOTES: 1,2,4,7,8,9 on the page
following these figures
A03213
A03215
Fig. 41 -- Horizontal Left Application -- Vent Elbow Left
Fig. 44 -- Horizontal Left Application -- Vent Elbow Up
SEE NOTES: 1,2,4,5,7,8,9 on the page
following these figures
SEE NOTES: 1,2,4,5,7,8,9 on the page
following these figures
A03214
A03216
Fig. 42 -- Horizontal Left Application -- Vent Elbow Right
then Up
Fig. 45 -- Horizontal Left Application -- Vent Elbow Right
SEE NOTES: 1,2,4,7,8,9 on the page
following these figures
SEE NOTES: 1,2,4,5,7,8,9 on the page
following these figures
A03218
A03219
Fig. 43 -- Horizontal Right Application -- Vent Elbow Right
Fig. 46 -- Horizontal Right Application -- Vent Elbow Left
then Up
31
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SEE NOTES: 1,2,4,5,7,8,9
A02068
Fig. 47 -- Horizontal Right Application--Vent Elbow Left
NOTES: Venting Notes for Fig. 35---47
1. For common vent, vent connector sizing and vent material: United States--- ---use the NFGC Canada--- ---use the CAN/CSA---B149.1---05
2. Immediately increase to 5---in. or 6---in. (127 or 152 mm) vent connector outside furnace casing when 5---in. (127 mm) vent connector is required, refer to
Note 1 above.
3. Side outlet vent for upflow and downflow installations must use Type B vent immediately after exiting the furnace, except when KGAVG0101DFG, Downflow
Vent Guard Kit, is used in the downflow position.
4. Type---B vent where required, refer to Note 1 above.
5. Four---in. (102 mm) single---wall (26 ga. min.) vent must be used inside furnace casing and when the KGAVG0101DFG Downflow Vent Guard Kit is used
external to the furnace.
6. Accessory Downflow Vent Guard Kit, KGAVG0101DFG required in downflow installations with lower vent configuration.
7. Chimney Adapter Kit may be required for exterior masonry chimney applications. Refer to Chimney Adapter Kit, KGACA02014FC or KGACA02015FC, for
sizing and complete application details.
8. Secure vent connector to furnace elbow with (2) corrosion---resistant sheet metal screws, spaced approximately 180_ apart.
9. Secure all other single wall vent connector joints with (3) corrosion resistant screws spaced approximately 120_ apart. Secure Type---B vent connectors per
vent connector manufacturer’s recommendations.
10. The total height of the vent and connector shall be at least seven feet (2 M) for the 154,000 Btuh gas input rate model when installed in a downflow applica-
tion with furnace elbow turned to left side with the connector elbow outside furnace casing pointing upward. (See Fig. 40.)
Caution!! For the following applications, use the minimum vertical heights as specified below.
For all other applications, follow exclusively the National Fuel Gas Code
MINIMUM VENT
DIAMETER
MINIMUM VERTICAL
VENT HEIGHT
FT. (M)**
FURNACE
ORIENTATION
VENT
ORIENTATION
FURNACE
INPUT(BTUH/HR)
IN. (mm)*
154,000
132,000
110,000(036/---12 only)
Vent elbow left, then
up Fig. 39
Downflow
5 (127)
12 (3.6)
Vent elbow right,
then up Fig. 42
Vent Elbow up Fig.
43
Vent elbow right Fig.
44
Vent elbow up then
left Fig. 37
154,000
132,000
154,000
132,000
Horizontal Left
Horizontal Left
Horizontal Left
Downflow
5 (127)
5 (127)
5 (127)
5 (127)
5 (127)
7 (.65)
7 (.65)
7 (.65)
10 (3.0)
10 (3.0)
154,000
110,000 (036/---12 only)
110,000 (036/---12 only)
Vent elbow up, then
right Fig. 40
Downflow
*4 in. (102 mm) inside casing or vent guard
**Including 4 in. (102 mm) vent section(s)
NOTE: All vent configurations must also meet National Fuel Gas Code venting requirements NFGC.
32
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A04127
Fig. 48 -- Using Tin Snips to Cut Tie Points
For the rectangular J--box knockout, use tin snips along the door
edge and use a sharp blow with a hammer to remove the
knockout. Remove any burrs and sharp edges.
!
CAUTION
For the knockouts in the other locations on the door (top and
sides), tin snips can also be used along the door edges; however,
the preferred method is to use a hammer and screwdriver to strike
a sharp blow (See Fig. 51.) directly to the knockout tie points or
use a hammer in the upper left corner of the desired knockout.
(See Fig. 52.) Remove any burrs and sharp edges.
CUT HAZARD
Failure to follow this caution may result in personal injury.
Sheet metal parts may have sharp edges or burrs. Use care
and wear appropriate protective clothing, safety glasses and
gloves when handling parts and servicing furnaces.
NOTE: If a knockout does not come out after two sharp blows,
pull and snip as needed to remove the knockout. Additional
blows may cause damage to the door.
NOTE: Vent connector length for connector sizing starts at
furnace vent elbow. The 4--in. (102 mm) vent elbow is shipped
for upflow configuration and may be rotated for other positions.
Remove the 3 screws that secure vent elbow to furnace, rotate
furnace vent elbow to position desired, re--install screws. The
factory--supplied vent elbow does NOT count as part of the
number of vent connector elbows.
The vent connector can exit the door through one of 5 locations
on the door.
1. Attach the single wall vent connector to the furnace vent
elbow, and fasten the vent connector to the vent elbow
with at least two field--supplied, corrosion--resistant, sheet
metal screws located 180_ apart.
NOTE: An accessory flue extension KGAFE0112UPH is
available to extend from the furnace elbow to outside the furnace
casing. If flue extension is used, fasten the flue extension to the
vent elbow with at least two field--supplied, corrosion--resistant,
sheet metal screws located 180_ apart. Fasten the vent connector
to the flue extension with at least two field--supplied, corrosion
resistant sheet metal screws located 180_ apart.
2. Vent the furnace with the appropriate connector as shown
in Fig. 35--47.
3. Orient the door to determine the correct location of the
door knockout to be removed.
4. Remove the correct U--shaped knockout in door.
NOTE: A number of techniques can be used to remove these
knockouts as seen in Fig. 48 through 52. The knockout in the
bottom of the door is unique due to its flanging and is more easily
removed by first cutting the two tie points at the edge of the door,
using aviation--type tin snips. (See Fig. 48.) A sharp blow to the
rounded end of the knockout (See Fig. 49.) will separate more tie
points and allow the knockout to be pulled loose. (See Fig. 50.)
Remove all burrs any sharp edges.
A04128
Fig. 49 -- Rounded End of Knockout
33
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An accessory Vent Guard Kit, KGAVG0101DFG is REQUIRED
for downflow applications for use where the vent exits through
the lower portion of the furnace casing door. Refer to the Vent
Guard Kit Instructions for complete details.
The horizontal portion of the venting system shall slope upwards
not less than 1/4--in. per linear ft. (6 mm/.3 M) from the furnace
to the vent and shall be rigidly supported every 5 ft. (1.5 M) or
less with metal hangers or straps to ensure there is no movement
after installation.
SIDEWALL VENTING
This furnace is not approved for direct sidewall horizontal
venting.
In the U.S.: Per section 10.3.4 of the NFPA 54 / ANSI
Z223.1--2006, any listed mechanical venter may be used, when
approved by the authority having jurisdiction.
In Canada: Per section 8.24.2 of the CAN/CSA--B149.1--05,
any listed mechanical venter may be used, when approved by the
authority having jurisdiction.
A04129
Fig. 50 -- Knockout Pulled Loose
Select the listed mechanical venter to match the Btuh input of the
furnace being vented. Follow all manufacturer’s installation
requirements for venting and termination included with the listed
mechanical venter.
START--UP, ADJUSTMENT, AND SAFETY
CHECK
Step 1 — General
!
WARNING
FIRE HAZARD
Failure to follow this warning could result in personal
injury, death and/or property damage.
This furnace is equipped with manual reset limit switches in
the gas control area. The switches open and shut off power
to the gas valve if a flame roll--out or overheating condition
occurs in the gas control area. DO NOT bypass the
switches. Correct problem before resetting the switches.
A04130
Fig. 51 -- Hammer and Screwdriver Used for Knockout
1. Maintain 115--v wiring and ground. Improper polarity will
result in rapid flashing LED and no furnace operation.
2. Make thermostat wire connections at the 24--v terminal
block on the furnace control. Failure to make proper con-
nections will result in improper operation. (See Fig. 23.)
3. Gas supply pressure to the furnace must be greater than
4.5--in. wc (0.16 psig ) but not exceed 14--in. wc (0.5
psig).
!
CAUTION
CUT HAZARD
Failure to follow this caution may result in personal injury.
Sheet metal parts may have sharp edges or burrs. Use care
and wear appropriate protective clothing, safety glasses and
gloves when handling parts and servicing furnaces.
A04131
Fig. 52 -- Remove Knockout with Hammer
!
CAUTION
4. Check all manual--reset switches for continuity.
5. Install blower compartment door. Door must be in place to
operate furnace.
BURN HAZARD
Failure to follow this caution may cause personal injury.
6. Setup switch descriptions The 2 stage furnace has DIP
switches used to select thermostat staging and blower off
delay timings. For switch locations on Furnace control
board, See Fig. 33 and 57.
Hot vent pipe is within reach of small children when
installed in downflow position.
See the following instruction.
7. Setup switch descriptions -- See Table 10.
34
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Table 10 – 2--Stage Furnace Setup Switch Description
SETUP
SWITCH NO.
SWITCH
NAME
NORMAL
POSITION
DESCRIPTION
OF USE
When OFF, allows 2---stage operation with a single stage thermostat.
Turn ON when using 2 stage thermostat to allow Low Heat opera---
tion when R to W/W1 closes and High Heat operation when R to
W/W1 and W2 close.
SW --- 1
Adaptive Heat Mode
OFF
Control blower OFF delay time. Used in conjunction with SW---3.
See Table 14.
SW --- 2
SW --- 3
Blower OFF delay
Blower OFF delay
ON or OFF
ON or OFF
Control blower OFF delay time. Used in conjunction with SW---2.
See Table 14.
5. Verify furnace shut down by lowering thermostat setting
below room temperature.
Step 2 — Start-Up Procedures
6. Verify furnace restarts by raising thermostat setting above
room temperature.
!
WARNING
Step 3 — Adjustments
FIRE AND EXPLOSION HAZARD
Failure to follow this warning could cause personal injury,
death and/or property damage.
!
WARNING
Never test for gas leaks with an open flame. Use a
commercially available soap solution made specifically for
the detection of leaks to check all connections.
FIRE HAZARD
Failure to follow this warning could result in injury, death
and/or property damage.
DO NOT bottom out gas valve regulator adjusting screw.
This can result in unregulated manifold pressure and result
in excess over--fire and heat exchanger failures.
1. Purge gas lines after all connections have been made.
2. Check gas lines for leaks.
!
WARNING
!
ELECTRICAL SHOCK HAZARD
CAUTION
Failure to follow this warning could result in personal
injury, or death.
FURNACE DAMAGE HAZARD
Failure to follow this caution may result in reduced furnace
life.
Blower access door switch opens 115--v power to control.
No component operation can occur unless switch is closed.
Caution must be taken when manually closing this switch
for service purposes.
DO NOT re--drill orifices. Improper drilling (burrs, out--of
round holes, etc.) can cause excessive burner noise and
misdirection of burner flames. This can result in flame
impingement of heat exchangers, causing failures. (See Fig.
49.)
3. To Begin Component Self--Test:
Remove blower access door. Disconnect the thermostat R
lead from furnace control board. Manually close blower
door switch. Short (jumper) the COM--24v terminal on
control to the TEST/TWIN 3/16--in. (8 mm) quick--con-
nect terminal on control until the LED goes out (approx-
imately 2 sec). Gas valve and humidifier will not be turned
on. Remove jumper from terminals. (See Fig. 33 and
Table 10.)
Furnace gas input rate on rating plate is for installations at
altitudes up to 2000 ft. (610 M). Furnace input rate must be
within +/--2% of furnace rating plate input. For altitudes above
5500 ft. (1676 M), a field--supplied high altitude pressure switch
is required.
1. Determine the correct gas input rate.
In the U.S.:
NOTE: The furnace control allows all components, except the
gas valve, to be run for short period of time. This feature helps
diagnose a system problem in case of a component failure.
Component test feature will not operate if any thermostat signal is
present at the control.
The input rating for altitudes above 2,000 ft. (610 M) must
be reduced by 4% for each 1,000 ft. (305 M) above sea
level.
For installations below 2000 ft. (610 M), refer to the unit
rating plate.
For installations above 2000 ft. (610 M), multiply the in-
put on the rating plate by the derate multiplier in Table 11
for the correct input rate.
Refer to service label attached to furnace or See Fig. 56.
Component test sequence is as follows:
a. LED will display previous status code 4 times.
b. Inducer motor starts on high--speed and continues to run
until Step g of component test sequence.
EXAMPLE:
c. Hot surface igniter is energized for 15 sec., then off.
d. Blower motor operates on LO--HEAT speed for 10 sec.
e. Blower motor operates on HI--HEAT speed for 10 sec.
f. Blower motor operates on COOL speed for 10 sec.
g. Inducer motor goes to low--speed for 10 sec., then stops.
88,000 BTUH INPUT FURNACE INSTALLED AT 4300 FT. (1310
M)
Derate
Multiplier
Factor
0.90
Furnace Input Rate
at Installation
Altitude
Furnace Input Rate
at Sea Level
88,000
X
X
=
=
79,200
h. Reconnect R lead to furnace control board, remove tape
from blower door switch and re--install blower door.
4. Operate furnace per instruction on inner door.
In Canada: The input rating must be reduced by 10% for
altitudes of 2,000 ft. (610 M) to 4,500 ft. (1372 M) above
35
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sea level by an authorized Gas Conversion Station or
Dealer. To determine correct input rate for altitude, see
example and use 0.90 as derate multiplier factor.
3. Adjust manifold pressure to obtain low fire input rate. (See
Fig. 53.)
a. Turn gas valve ON/OFF switch to OFF.
2. Determine the correct orifice and manifold pressure adjust-
ment. All models in all positions except Low NOx models
in downflow and horizontal positions use Table 15
(22,000 BTUH per burner).
b. Remove manifold pressure tap plug from gas valve.
c. Connect a water column manometer or similar device to
manifold pressure tap.
d. Turn gas valve ON/OFF switch to ON.
Table 11 – Altitude Derate Multiplier for U.S.A.
ALTITUDE
FT. (M)
PERCENT
OF DERATE
DERATE MULTIPLIER
FACTOR*
0–2000
0
1.00
0.90
0.86
0.82
0.78
0.74
0.70
0.66
0.62
(0---610)
2001–3000
(610---914)
3001–4000
(914---1219)
4001–5000
(1219---1524)
5001–6000
1524---1829)
6001–7000
(1829---2134)
7001–8000
(2134---2438)
8001–9000
(2438---2743)
9001–10,000
(2743---3048)
8–12
12–16
16–20
20–24
24–28
28–32
32–36
36–40
* Derate multiplier factors are based on midpoint altitude for altitude
range.
Low NOx models in downflow or horizontal positions MUST
use Table 16 (21,000 BTUH per burner). See input listed on
rating plate.
a. Obtain averageyearly gasheat value(at installed altitude)
from local gas supplier.
A06667
Fig. 53 -- Redundant Automatic Gas Control Valve
b. Obtain average yearly gas specific gravity from local gas
supplier.
e. Move setup switch LHT (SW--1) on furnace control to
ON position to lock furnace in low--heat operation. (See
Fig. 33 and Table 10.)
c. Find installation altitude in Table 15 or 16.
d. Find closest natural gas heat value and specific gravity
in Table 15 or 16
f. Manually close blower door switch.
g. Jumper R and W/W1 thermostat connections on control
to start furnace. (See Fig. 33.)
e. Follow heat value and specific gravity lines to point of
intersection to find orifice size and low--and high--heat
manifold pressure settings for proper operation.
h. Remove regulator adjustment cap from low--heat gas
valve pressure regulators. (See Fig. 53.) Turn low--heat
adjusting screw (3/16 in. (5 mm) or smaller flat tipped
screwdriver) counterclockwise (out) to decrease input
rate or clockwise (in) to increase input rate.
f. Check and verify burner orifice size in furnace. NEVER
ASSUME ORIFICE SIZE. ALWAYS CHECK AND
VERIFY.
g. Replace orifice with correct size, if required by Table 15
or 16. Use only factory--supplied orifices. See
EXAMPLE 2.
NOTE: DO NOT set low--heat manifold pressure less than
1.4--in wc or more than 1.7--in. wc for natural gas. If manifold
pressure is outside this range, change main burner orifices.
EXAMPLE 2: (0--2000 ft. / 0--610 M altitude)
For 22,000 Btuh per burner application, use Table 15.
Heating value = 1000 Btuh/cu ft.
i. Install low--heat regulator adjustment cap.
j. Leave manometer or similar device connected and pro-
ceed to Step 4.
Specific gravity = 0.62
NOTE: If orifice hole appears damaged or it is suspected to have
been re--drilled, check orifice hole with a numbered drill bit of
correct size. Never re--drill an orifice. A burr--free and squarely
aligned orifice hole is essential for proper flame characteristics.
Therefore: Orifice No. 43*
Manifold pressure: 3.7--in. wc for high--heat
1.6--in. wc for low--heat
4. Verify natural gas low--heat input rate by clocking meter.
* Furnace is shipped with No. 43 orifices. In this example
all main burner orifices are the correct size and do not need
to be changed to obtain proper input rate.
NOTE: Gas valve regulator adjustment caps must be in place for
proper input to be clocked.
a. Turn off all other gas appliances and pilots served by the
meter.
36
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b. Run for 3 minutes in low--heat operation.
5. Set low--heat temperature rise. The furnace must operate
within the temperature rise ranges specified on the furnace
rating plate. Do not exceed temperature rise ranges spe-
cified on unit rating plate for high--and low--heat.
Determine the temperature rise as follows:
c. Measure time (in sec) for gas meter to complete 1 revolu-
tion and note reading. The 2 or 5 cubic feet dial provides
a more accurate measurement of gas flow.
NOTE: Blower access door must be installed when taking
temperature rise reading. Leaving blower access door off will
result in incorrect temperature measurements.
!
WARNING
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Disconnect 115--v electrical power before changing speed
tap.
BURNER
ORIFICE
a. Verify unit is running in low heat per Step 3. Place ther-
mometers in return and supply ducts as close to furnace
as possible. Be sure thermometers do not see radiant heat
from heat exchangers. Radiant heat affects temperature
rise readings. This practice is particularly important with
straight--run ducts.
A93059
Fig. 54 -- Orifice Hole
d. Refer to Table 12 for cubic ft. of gas per hr.
b. When thermometer readings stabilize, subtract return--air
temperaturefromsupply--air temperatureto determineair
temperature rise.
e. Multiply gas rate cu ft. /hr by heating value (Btuh/cu ft.
) to obtain input. If clocked rate does not match required
input from Step 1, increase manifold pressure to increase
input or decrease manifold pressure to decrease input.
Repeat steps b through e until correct low heat input is
achieved. Re--install low--heat regulator seal cap on gas
valve.
NOTE: If the temperature rise is outside this range, first check:
(1.) Gas input for low heat operation.
(2.) Derate for altitude if applicable.
(3.) Return and supply ducts for excessive restrictions
causing static pressures greater than 0.50--in. wc.
37
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Table 12 – Gas Rate (cu ft. /hr)
SECONDS
SECONDS
SIZE OF TEST DIAL
SIZE OF TEST DIAL
FOR 1
FOR 1
1 CU FT.
2 CU FT.
5 CU FT.
1 CU FT.
2 CU FT.
5 CU FT.
REVOLUTION
REVOLUTION
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
360
327
300
277
257
240
225
212
200
189
180
171
164
157
150
144
138
133
129
124
120
116
113
109
106
103
100
97
720
655
600
555
514
480
450
424
400
379
360
343
327
313
300
288
277
267
257
248
240
232
225
218
212
206
200
195
189
185
180
176
172
167
164
160
157
153
150
147
1800
1636
1500
1385
1286
1200
1125
1059
1000
947
900
857
818
783
750
720
692
667
643
621
600
581
563
545
529
514
500
486
474
462
450
439
429
419
409
400
391
383
375
367
50
72
71
69
68
67
65
64
63
62
61
60
58
56
54
53
51
50
48
47
46
45
44
43
42
41
40
39
38
38
37
36
35
35
34
33
33
32
31
30
144
141
138
136
133
131
129
126
124
122
120
116
112
109
106
103
100
97
360
355
346
340
333
327
321
316
310
305
300
290
281
273
265
257
250
243
237
231
225
220
214
209
205
200
196
192
188
184
180
178
173
170
167
164
161
155
150
51
52
53
54
55
56
57
58
59
60
62
64
66
68
70
72
74
76
95
78
92
80
90
82
88
84
86
86
84
88
82
90
80
92
78
94
76
95
96
75
92
98
74
90
100
102
104
106
108
110
112
116
120
72
88
71
86
69
84
68
82
67
80
65
78
64
76
62
75
60
73
c. Adjust air temperature rise by adjusting blower speed. In-
crease blower speed to reduce temperature rise. Decrease
blower speed to increase temperature rise. For low heat,
speed selection can be low (factory setting), med--low, or
med (5--speed blowers only).
d. Remove thermostat jumpers and release Blower Access
Door Switch.
e. To change motor speed selection for low heat, remove
blower motor lead from control LO--HEAT terminal.
(See Fig. 33.) Select desired blower motor speed lead
from 1 of the other terminals and relocate it to the LO--
HEAT terminal. (See Table 13 for lead color identifica-
tion). Reconnect original lead to SPARE terminal.
a. Remove high fire regulator adjustment cap from gas
valve pressure regulator.
b. Manually close blower access door switch.
c. Jumper R, W/W1 and W2 thermostat connections on
control to run furnace in high heat. (See Fig. 33.)
d. d. Turn high--heat adjusting screw (3/16--in. (5 mm) or
smaller flat tipped screwdriver) counterclockwise (out)
to decrease input rate or clockwise (in) to increase rate.
e. Re--install high--fire adjustment caps.
f. Leave manifold or similar device connected and proceed
to Step 7.
NOTE: DO NOT set high--heat manifold pressure less than
3.2--in. wc or more than 3.8--in. wc for natural gas. If manifold
pressure is outside this range, change main burner orifices.
f. Repeat steps a through e.
7. Verify natural gas high heat input rate by clocking meter.
NOTE: Gas valve regulator adjustment caps must be in place for
proper input to be clocked.
!
CAUTION
FURNACE OVERHEATING HAZARD
a. Turn off all other gas appliances and pilots served by the
meter.
Failure to follow this caution may result in reduced furnace
life.
b. Run for 3 minutes in high--heat operation.
c. Measure time (in sec) for gas meter to complete 1 revolu-
tion and note reading.
Recheck temperature rise. It must be within limits specified
on the rating plate. Recommended operation is at the
midpoint of rise range or slightly above.
d. Refer to Table 12 for cubic ft. of gas per hr.
e. Multiply gas rate cu ft. /hr by heating value (Btuh/cu ft.)
to obtain input.
g. When correct low heat input rate and temperature rise is
achieved, proceed to Step 6.
6. Adjust Manifold Pressure to Obtain High Heat Rate
38
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NOTE: Using the 2 cu. ft. or 5 cu. ft. gas meter dial provides
greater accuracy in verifying gas input rate.
!
WARNING
If clocked rate does not match required input from Step 1,
increase manifold pressure to increase input or decrease manifold
pressure to decrease input. Repeat steps b through e until correct
high heat input is achieved. Re--install high--heat regulator seal
cap on gas valve.
FIRE HAZARD
Failure to reinstall manifold pressure tap plug in gas valve
could result in personal injury, property damage or death.
Reinstall manifold pressure tap plug in gas valve to prevent
gas leak.
8. Set high heat temperature rise.
Jumper R to W/W1 and W2 to check high--gas--heat tem-
perature rise. Do not exceed temperature rise ranges spe-
cified on furnace rating plate for high heat. The furnace
must operate within the temperature rise ranges specified
on the furnace rating plate.
j. Remove thermostat jumper wire from furnace control
board.
k. Turn LHT switch OFF.
Determine the air temperature rise as follows:
l. Turn gas valve ON/OFF switch to ON.
m. Proceed to Step 9, “Set Blower Off Delay” before in-
stalling blower access door.
NOTE: Blower access door must be installed when taking
temperature rise reading. Leaving blower access door off will
result in incorrect temperature measurements.
a. Verify the furnace is operating in high heat per Step 6.
Place thermometers in return and supply ducts as close
to furnace as possible. Be sure thermometers do not see
radiant heat from heat exchangers. Radiant heat affects
temperature rise readings.This practiceis particularly im-
portant with straight--run ducts.
!
CAUTION
FURNACE OVERHEATING HAZARD
Failure to follow this caution may result in reduced furnace
life.
b. When thermometer readings stabilize, subtract return--air
temperaturefromsupply--air temperatureto determineair
temperature rise.
Recheck temperature rise. It must be within limits specified
on the rating plate. Recommended operation is at the
midpoint of rise range or slightly above.
NOTE: If the temperature rise is outside this range, first check:
(1.) Gas input for low--and high--heat operation.
(2.) Derate for altitude if applicable.
9. Set Blower Off Delay
a. Remove Blower Access Door if installed.
b. Turn Dip switch 2 and 3 ON or OFF for desired blower
off delay. (See Table 14 and Fig 34.)
(3.) Return and supply ducts for excessive restrictions
causing static pressures greater than 0.50--in. wc.
(4.) Dirty filter.
10. Set thermostat heat anticipator.
c. Adjust air temperature rise by adjusting blower speed. In-
crease blower speed to reduce temperature rise. Decrease
blower speed to increase temperature rise. For high heat,
speed selection can be med--high, med (5--speed blowers
only), or med--low (factory setting).
a. Mechanical thermostat -- Set thermostat heat anticipator
to match the amp. draw of the electrical components in
the R--W/W1 circuit. Accurate amp. draw readings can
be obtainedat thewires normallyconnected tothermostat
subbase terminals, R and W. The thermostat anticipator
should NOT be in the circuit while measuring current.
!
(1.) Set LHT switch on furnace control board to ON.
(2.) Remove thermostat from sub--base or from wall.
WARNING
ELECTRICAL SHOCK HAZARD
(3.) Connect an amp. meter as shown in Fig. 55 across
the R and W subbase terminals or R and W wires at
wall.
Failure to follow this warning could result in personal
injury or death.
Disconnect 115--v electrical power before changing speed
tap.
(4.) Record amp. draw across terminals when furnace is
in low heat and after blower starts.
(5.) Set heat anticipator on thermostat per thermostat in-
structions and install on subbase or wall.
d. To change motor speed selection for high heat, remove
blower motor lead from control HI--HEAT terminal. (See
Fig. 33.) Select desired blower motor speed lead from 1
of the other terminals and relocate it to the HI--HEAT ter-
minal. DO NOT use the low--heattap thatwas already set.
(See Table 13 for lead color identification). Reconnect
original lead to SPARE terminal.
(6.) Turn LHT switch OFF.
(7.) Install blower access door.
b. Electronic thermostat: Set cycle rate for 3 cycles per hr.
11. Set airflow CFM for cooling
Select the desired blower motor speed lead for cooling air-
flow. See Table 5--Air Delivery--CFM (With Filter). See
Table 13 for lead color identification.
e. Repeat steps a thru e.
f. When correct high heat input rate and temperature rise is
achieved, turn gas valve ON/OFF switch to OFF.
Table 13 – Speed Selection
COLOR
White
Black
Yellow
Orange†
Blue
SPEED
Common
High
Me d --- H ig h
Med
AS SHIPPED
BLW
g. Release Blower Access Door switch.
h. Remove manometer or similar device from gas valve.
COOL
SPARE
SPARE
HI---HEAT
LO HEAT
i. Re--install manifold pressure tap plug in gas valve. (See
Fig 54.)
Me d --- L o w
Low*
Red
* Continuous---blower speed---as shipped default
{ Not all models equipped with 5 speed motors
39
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Table 14 – 2--Stage Furnace Blower OFF delay Setup Switch
DESIRED HEATING MODE
BLOWER OFF DELAY (SEC.)
SETUP SWITCH
S W --- 2
SETUP SWITCH
S W --- 3
90
OFF
OFF
ON
OFF
ON
OFF
ON
120
150
180
ON
guard switch did not function properly and correct condi-
tion.
f. Remove blockage from furnace vent elbow.
g. Switch will auto--reset when it cools.
h. Re--install vent connector.
THERMOSTAT SUBBASE
TERMINALS WITH
THERMOSTAT REMOVED
(ANITICIPATOR, CLOCK, ETC.,
MUST BE OUT OF CIRCUIT.)
HOOK-AROUND
AMMETER
NOTE: Should switch remain open longer than 3 minutes,
furnace control board will lockout the furnace for 3 hours. To
reset furnace control board, turn thermostat below room
temperature or from HEAT to OFF and turn 115--v power OFF,
then back ON.
R
Y
W
G
3. Check Pressure Switch(es)
This control proves operation of the draft inducer blower.
a. Turn off 115--v power to furnace.
b. Disconnect inducer motor lead wires from wire harness.
c. Turn on 115--v power to furnace.
10 TURNS
d. Set thermostat to “call for heat” and wait 1 minute. When
pressure switch is functioning properly, hot surface ig-
niter should NOT glow and control diagnostic light
flashes a status code 32. If hot surface igniter glows when
inducer motor is disconnected, shut down furnace imme-
diately.
FROM UNIT 24-V
CONTROL TERMINALS
0.5 AMPS FOR THERMOSTAT
ANTICIPATOR SETTING
5.0 AMPS ON AMMETER
10 TURNS AROUND JAWS
=
EXAMPLE:
e. Determine reason pressure switch did not function prop-
erly and correct condition.
f. Turn off 115--v power to furnace.
A96316
Fig. 55 -- Amp. Draw Check with Ammeter
g. Reconnect inducer motor wires, replace outer door, and
turn on 115--v power.
Step 4 — Check Safety Controls
The flame sensor, gas valve, and pressure switch were all checked
in the Start--up procedure section as part of normal operation.
h. Blower will run for 90 seconds before beginning the call
for heat again.
1. Check Main Limit Switch(es)
i. Furnace should ignite normally.
This control shuts off combustion system and energizes
air--circulating blower motor, if furnace overheats. By us-
ing this method to check limit control, it can be established
that limit is functioning properly and will operate if there
is a restricted return--air supply or motor failure. If limit
control does not function during this test, cause must be
determined and corrected.
Step 5 — Checklist
1. Put away tools and instruments. Clean up debris.
2. Verify that switches for LHT and OFF--DELAY are
blower OFF--DELAY are selected as desired.
3. Verify that blower and burner access doors are properly in-
stalled.
a. Run furnace for at least 5 minutes.
4. Cycle test furnace with room thermostat.
b. Gradually block off return air with a piece of cardboard
or sheet metal until the limit trips.
5. Check operation of accessories per manufacturer fs in-
structions.
c. Unblock return air to permit normal circulation.
d. Burners will re--light when furnace cools down.
6. Review User’s Guide with owner.
7. Attach literature packet to furnace.
2. Check draft safeguard switch.
The purpose of this control is to cause the safe shutdown
of the furnace during certain blocked vent conditions.
a. Verify vent pipe is cool to the touch.
b. Disconnect power to furnace and remove vent connector
from furnace vent elbow.
c. Restore power to furnace and set room thermostat above
room temperature.
d. After normal start--up, allow furnace to operate for 2
minutes, then block vent elbow in furnace 80% of vent
area with a piece of flat sheet metal.
e. Furnace should cycle off within 2 minutes. Ifgas doesnot
shut off within 2 minutes, determine reason draft safe-
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Table 15 – Orifice Size* and Manifold Pressures (In wc) for Gas Input Rate
A08485
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Table 15 -- Orifice Size and Manifold Pressures (In wc) for Gas Input Rate (cont.)
A08485A
42
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Table 16 – Orifice Size* and Manifold Pressures (In wc) for Gas Input Rate
A08219
43
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Table 16 -- Orifice Size* and Manifold Pressures (In wc) for Gas Input Rate (cont.)
A08219A
44
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ELECTRICAL CONTROLS AND WIRING
SERVICE AND MAINTENANCE
PROCEDURES
!
WARNING
!
WARNING
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
FIRE, PERSONAL INJURY AND UNIT DAMAGE
HAZARD
There may be more than one electrical supply to the
furnace. Check accessories and cooling unit for additional
electrical supplies that must be shut off during furnace
servicing.
Failure to follow this warning could result in personal injury,
death and/or property damage.
The ability to properly perform maintenance on this
equipment requires certain knowledge, mechanical skills,
tools, and equipment. If you do not possess these, do not
attempt to perform any maintenance on this equipment other
than those procedures recommended in the User’s Manual.
The electrical ground and polarity for 115--v wiring must be
properly maintained. Refer to Fig. 23 for field wiring information
and to Fig. 57 for furnace wiring information.
NOTE: If the polarity is not correct, the STATUS LED on the
control will flash rapidly and prevent the furnace from heating.
The control system also requires an earth ground for proper
operation of the control and flame--sensing electrode.
!
WARNING
ELECTRICAL SHOCK, FIRE OR EXPLOSION
HAZARD
The 24--v circuit contains an automotive--type, 3--amp. fuse
located on the control. (See Fig. 31.) Any shorts of the 24--v
wiring during installation, service, or maintenance will cause this
fuse to blow. If fuse replacement is required, use ONLY a 3--amp.
fuse. The control LED will display status code 24 when fuse
needs to be replaced.
Failure to follow this warning could result in personal injury
or death, or property damage.
Before servicing, disconnect all electrical power to furnace.
Verify proper operation after servicing.
Proper instrumentation is required to service electrical controls.
The control in this furnace is equipped with a Status Code LED
(Light--Emitting Diode) to aid in installation, servicing, and
troubleshooting. It can be viewed through the sight glass in
blower access door. The furnace control LED is either ON
continuously, rapid flashing, or a code composed of 2 digits. The
first digit is the number of short flashes, the second digit is the
number of long flashes.
!
CAUTION
UNIT OPERATION HAZARD
Failure to follow this caution may result in improper unit
operation or failure of unit components.
For an explanation of status codes, refer to service label located
on blower access door or Fig. 56, and the troubleshooting guide
which can be obtained from your distributor.
Label all wires prior to disconnection when servicing
controls. Wiring errors can cause improper and dangerous
operation.
See Fig. 61 for a brief Troubleshooting guide.
For Controls with an Amber LED
The stored status codes will NOT be erased from the control
memory, if 115-- or 24--v power is interrupted. The control will
store up to five (5) status codes.
!
CAUTION
ENVIRONMENTAL HAZARD
1. To retrieve status codes, proceed with the following:
Failure to follow this caution may result in environmental
pollution.
NOTE: NO thermostat signal may be present at control, and all
blower--OFF delays must be completed.
Remove and recycle all components or materials (i.e. oil,
refrigerant, control board, etc.) before unit final disposal.
a. Leave 115--v power to furnace turned on.
b. Remove outer access door.
c. Look into blower access door sight glass for current LED
status. Removing blower access door will open blower
access door switch and terminate 115--v power to control
so that status code is not displayed.
Step 1 — Introduction
GENERAL
These instructions are written as if the furnace is installed in an
upflow application. An upflow furnace application is where the
blower is located below the combustion and controls section of
the furnace, and conditioned air is discharged upward. Since this
furnace can be installed in any of the 4 positions shown in Fig. 4,
you must revise your orientation to component location
accordingly.
d. BRIEFLY remove insulated terminal wire from the draft
safeguard (DSS) switch until LED goes out, then recon-
nect it.
NOTE: If wire to DSS is disconnected longer than 4 sec, main
blower starts, and retrieval request is ignored.
2. When above items have been completed, the LED flashes
status code 4 times. Record this status code for further
troubleshooting. After the LED flashes status code four
times, BRIEFLY remove wire again from DSS switch un-
til LED goes out, then reconnect it to retrieve previous
status code (if available). Repeat as needed for more previ-
ous status codes or until Code 11 appears.
45
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SERVICE
If status code recall is needed, briefly remove then reconnect one main limit wire to display last stored status code. On RED LED boards do not remove power or blower door before initiating status code recall.
LED CODE
STATUS
CONTINUOUS OFF - Check for 115VAC at L1 and L2, and 24VAC at SEC-1 and SEC-2.
CONTINUOUS ON - Control has 24VAC power.
RAPID FLASHING - Line voltage (115VAC) polarity reversed. If twinned, refer to twinning kit instructions.
EACH OF THE FOLLOWING STATUS CODES IS A TWO DIGIT NUMBER WITH THE FIRST DIGIT DETERMINED BY THE NUMBER OF SHORT FLASHES AND THE SECOND DIGIT BY THE NUMBER OF LONG FLASHES.
32 LOW-HEAT PRESSURE SWITCH DID NOT CLOSE OR REOPENED - If open longer than
five minutes, inducer shuts off for 15 minutes before retry. If opens during blower on-delay
period, blower will come on for the selected blower off-delay. Check for:
11 NO PREVIOUS CODE - Stored status code is erased automatically after 72 hours.
On RED LED boards stored status codes can also be erased when power
(115 VAC or 24 VAC) to control is interrupted.
- Excessive wind
- Restricted vent
- Defective inducer motor
- Low inducer voltage (115 VAC)
- Low inlet gas pressure (if LGPS used)
12 BLOWER ON AFTER POWER UP (115 VAC or 24 VAC) -Blower runs for the
selected blower off-delay time, if unit is powered up during a call for heat
(R-W/W1 closed) or (R-W/W1) opens during blower on-delay.
- Proper vent sizing
- Defective pressure switch
- Inadequate combustion air supply
- Disconnected or obstructed pressure tubing
13 LIMIT CIRCUIT LOCKOUT - Lockout occurs if a limit, draft safeguard, flame rollout,
or blocked vent switch (if used) is open longer than 3 minutes.
33 LIMIT CIRCUIT FAULT - Indicates a limit, draft safeguard, flame rollout, or blocked vent
switch (if used) is open. Blower will run for 4 minutes or until open switch remakes
whichever is longer. If open longer than 3 minutes, code changes to lockout #13. If open
less than 3 minutes status code #33 continues to flash until blower shuts off. Flame rollout
switch and BVSS require manual reset. Check for: - Dirty filter or restricted duct system
- Control will auto reset after three hours.
- Refer to #33.
14 IGNITION LOCKOUT - Control will auto-reset after three hours. Refer to #34.
21 GAS HEATING LOCKOUT - Control will NOT auto reset.
Check for: - Mis-wired gas valve
- Defective control (valve relay)
- Defective blower motor or capacitor
- Defective switch or connections
- Proper vent sizing
- Loose blower wheel
- Restricted vent
- Excessive wind
22 ABNORMAL FLAME-PROVING SIGNAL - Flame is proved while gas valve is de-
energized. Inducer will run until fault is cleared. Check for:
- Inadequate combustion air supply (Flame Roll-out Switch open).
- Leaky gas valve
- Stuck-open gas valve
34 IGNITION PROVING FAILURE - Control will try three more times before lockout #14 occurs.
If flame signal lost during blower on-delay period, blower will come on for the selected
blower off-delay. Check for: - Oxide buildup on flame sensor (clean with fine steel wool)
- Proper flame sense microamps (.5 microamps D.C. min., 4.0 - 6.0 nominal)
23 PRESSURE SWITCH DID NOT OPEN Check for: - Obstructed pressure tubing
- Pressure switch stuck closed
24 SECONDARY VOLTAGE FUSE IS OPEN Check for: - Short circuit in secondary
voltage (24VAC) wiring.
- Manual valve shut-off
- Control ground continuity
- Low inlet gas pressure
- Defective Hot Surface Ignitor
31 HIGH-HEAT PRESSURE SWITCH OR RELAY DID NOT CLOSE OR REOPENED
Control relay may be defective, refer to status code #32
- Gas valve defective or gas valve turned off
- Inadequate flame carryover or rough ignition
- Flame sensor must not be grounded
COMPONENT TEST
- Green/Yellow wire MUST be connected to furnace sheet metal
To initiate the component test sequence, shut OFF the room thermostat or disconnect the
"R" thermostat lead. Briefly short the TEST/TWIN terminal to the "Com 24V" terminal.
Status LED will flash last status code and then turn ON the inducer motor. The inducer
motor will start in HIGH speed and remain on HIGH speed until the end of the test then
shift to LOW speed for 7 to 15 seconds. The hot surface igniter, blower motor LO HEAT
speed, blower motor HI HEAT speed, and blower motor COOL speed will be turned ON for
10-15 seconds each. Gas Valve and Humidifier will not be turned on. When the blower is
turned OFF the inducer will be switched to low-speed for 10 seconds.
43 LOW-HEAT PRESSURE SWITCH OPEN WHILE HIGH-HEAT PRESSURE SWITCH IS
CLOSED - Check for:
- Disconnected or obstructed pressure tubing
- Low-heat pressure switch stuck open
- Mis-wired pressure switches
- Low inlet gas pressure (if LGPS used)
45 CONTROL CIRCUITRY LOCKOUT Auto-reset after one hour lockout due to;
- Gas valve relay stuck open
- Flame sense circuit failure
- Software check error
Reset power to clear lockout. Replace control if status code repeats.
327598-101 REV. C
A04210
Fig. 56 -- Service Label
Step 2 — Care and Maintenance
!
WARNING
!
WARNING
CARBON MONOXIDE POISONING AND FIRE
HAZARD
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury, death, and/or property damage.
Failure to follow this warning could result in personal
injury, death and/or property damage.
Never operate unit without a filter or with filter access door
removed.
Never store anything on, near, or in contact with the
furnace, such as:
1. Spray or aerosol cans, rags, brooms, dust mops,
vacuum cleaners, or other cleaning tools.
2. Soap powders, bleaches, waxes or other cleaning
compounds, plastic or plastic containers, gasoline,
kerosene, cigarette lighter fluid, dry cleaning fluids,
or other volatile fluids.
3. Paint thinners and other painting compounds, paper
bags, or other paper products. Explosure to these
materials could lead to corrosion of the heat
exchanger.
!
CAUTION
CUT HAZARD
Failure to follow this caution may result in personal injury.
Sheet metal parts may have sharp edges or burrs. Use care
and wear appropriate protective clothing, safety glasses and
gloves when handling parts and servicing furnaces.
The minimum maintenance on this furnace is as follows:
For continuing high performance and to minimize possible
furnace failure, periodic maintenance must be performed on this
furnace. Consult your local dealer about proper frequency of
maintenance and the availability of a maintenance contract.
1. Check and clean air filter each month or more frequently if
required. Replace if torn.
2. Check blower motor and wheel for cleanliness each heat-
ing and cooling season. Clean as necessary.
3. Check electrical connections for tightness and controls for
proper operation each heating season. Service as neces-
sary.
!
WARNING
ELECTRICAL SHOCK AND FIRE HAZARD
4. Inspect burner compartment before each heating season
for rust, corrosion, soot or excessive dust. If necessary,
have furnace and burner serviced by a qualified service
agency.
5. Inspect the vent pipe/vent system before each heating sea-
son for rust, corrosion, water leakage, sagging pipes or
broken fittings. Have vent pipes/vent system serviced by a
qualified service agency.
Failure to follow this warning could result in personal
injury, death or property damage.
Turn off the gas and electrical supplies to the unit before
performing any maintenance or service. Follow the
operating instructions on the label attached to the furnace.
6. Inspect any accessories attached to the furnace such as a
humidifier or electronic air cleaner. Perform any service or
maintenance to the accessories as recommended in the ac-
cessory instructions.
46
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A07125
Fig. 57 -- Wiring Diagram
47
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TABLE 17 – FILTER SIZE INFORMATION (IN. / MM)
FILTER SIZE
FURNACE CASING WIDTH
SIDE
RETURN
BOTTOM
RETURN
FILTER TYPE
16 x25 x 3/4
14 x25 x 3/4
14---1/2 (368)
17---1/2 (445)
21 (533)
Washable*
Washable*
Washable*
Washable*
(406 x635 x 19)
(356 x635 x 19)
16 x25 x 3/4
(406 x635 x 19)
16 x25 x 3/4
(406 x635 x 19)
16 x25 x 3/4
(406 x635 x 19)
16 x25 x 3/4
(406 x635 x 19)
20 x25 x 3/4
(508 x635 x 19)
24 x25 x 3/4
(610 x635 x 19)
24 (610)
* Recommended
** Some furnaces may have 2 filters.
CLEANING AND/OR REPLACING AIR FILTER
To ensure long life and high efficiency, clean accumulated dirt
and grease from blower wheel and motor annually.
The air filter arrangement will vary depending on the application.
The inducer and blower motors are pre--lubricated and require no
additional lubrication. These motors can be identified by the
absence of oil ports on each end of the motor.
NOTE: If the filter has an airflow direction arrow, the arrow
must point towards the blower.
Clean blower motor and wheel as follows:
1. Turn off electrical supply to furnace.
!
CAUTION
2. Loosen the thumbscrew from outer door and remove outer
door.
CUT HAZARD
Failure to follow this caution may result in personal injury.
3. For downflow or horizontal furnaces having vent pipes
within the furnace that pass in front of the blower access
door:
Sheet metal parts may have sharp edges or burrs. Use care
and wear appropriate protective clothing, safety glasses and
gloves when handling parts and servicing furnaces.
a. Disconnect vent connector from furnace vent elbow.
b. Disconnect and remove short piece of vent pipe from
within furnace.
Media cabinet filter procedures:
NOTE: Media Cabinet is included with two--stage furnace.
4. Remove 2 screws from blower access door and remove
blower access door.
5. Disconnect blower leads from furnace control. Record
wire color and location for reassembly. All other factory
wires can be left connected, but field thermostat connec-
tions may need to be disconnected depending on their
length and routing.
1. Turn off electrical supply to furnace before removing filter
access door.
2. Remove filter cabinet door.
3. Slide filter out of cabinet.
4. If equipped with permanent, washable 3/4--in. (19 mm) fil-
ter, clean filter by spraying cold tap water through filter in
opposite direction of airflow. Rinse filter and let dry. Oil-
ing or coating of the filter is not recommended. See Table
17 for size information.
6. Remove 2 screws holding control box to blower shelf.
7. Hang control box from front of furnace casing and away
from blower compartment.
8. Remove 2 screws holding blower assembly to blower
deck and slide blower assembly out of furnace.
9. Clean blower wheel and motor using a vacuum with soft
brush attachment. Blower wheel blades may be cleaned
with a small paint or flux brush. Do not remove or disturb
balance weights (clips) on blower wheel blades.
5. If equipped with factory--specified disposable media filter,
replace only with media filter having the same part num-
ber and size. For expandable replacement media, refer to
the instructions included with the replacement media. If
equipped with accessory KGAFR0301ALL external filter
rack. See Table 17.
10. Vacuum any loose dust from blower housing, wheel and
motor.
6. Slide filter into cabinet.
7. Replace filter cabinet door.
11. If a greasy residue is present on blower wheel, remove
wheel from the blower housing and wash it with an appro-
priate degreaser. To remove wheel:
8. Turn on electrical supply to furnace.
BLOWER MOTOR AND WHEEL
NOTE: Before disassembly, mark blower mounting arms, motor,
and blower housing so motor and each arm is positioned at the
same location during reassembly.
!
WARNING
ELECTRICAL SHOCK HAZARD
a. Disconnectcapacitorwires(if equipped)and groundwire
attached to blower housing.
Failure to follow this warning could result in personal
injury or death.
b. Remove screws securing cutoff plate and remove cutoff
plate from housing.
Blower access door switch opens 115--v power to control.
No component operation can occur unless switch is closed.
Caution must be taken when manually closing this switch
for service purposes.
c. Loosen set screw holding blower wheel on motor shaft
(160+/--20 in.--lb. when reassembling).
d. Remove bolts holding motor to blower housing and slide
motor out of wheel (40+/--10in.--lb. whenreassembling).
NOTE: The blower wheel should not be dropped or bent as
balance will be affected.
e. Remove blower wheel from housing.
f. Clean wheel and housing.
The following steps should be performed by a qualified
service agency.
12. Reassemble motor and blower by reversing steps 11e,
through 11a. Be sure to reattach ground wire to the blower
housing.
48
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13. Verify that blower wheel is centered in blower housing
and set screw contacts the flat portion of the motor shaft.
Loosen set screw on blower wheel and reposition if neces-
sary.
cycle. Turn outdoor circuit breaker on after completing
cooling cycle.
CLEANING HEAT EXCHANGER
The following steps should be performed by a qualified
service agency:
14. Spin the blower wheel by hand to verify that the wheel
does not rub on the housing.
NOTE: If the heat exchangers get a heavy accumulation of soot
and carbon, they should be replaced rather than trying to clean
them thoroughly. A build--up of soot and carbon indicates that a
problem exists which needs to be corrected, such as improper
adjustment of manifold pressure, insufficient or poor quality
combustion air, incorrect size or damaged manifold orifice(s),
improper gas, or a restricted heat exchanger. Action must be taken
to correct the problem.
15. Reinstall blower assembly in furnace.
16. Reinstall control box assembly in furnace.
!
CAUTION
UNIT DAMAGE HAZARD
Failure to follow this caution may result in shortened heat
exchanger life.
If it becomes necessary to clean the heat exchangers because of
dust or corrosion, proceed as follows:
Heating fan speed(s) MUST be adjusted to provide proper
air temperature rise as specified on the rating plate.
Recommended operation is at the midpoint of the rise range
or slightly above. Refer to “SET TEMPERATURE RISE”
under START--UP, ADJUSTMENT, and SAFETY
CHECK.
1. Turn OFF gas and electrical power to furnace.
2. Remove outer access door.
3. Disconnect vent connector from furnace vent elbow.
4. For downflow or horizontal furnace having an internal
vent pipe, remove internal vent pipe within the casing.
5. Disconnect wires to the following components. Mark
wires to aid in reconnection of (be careful when discon-
necting wires from switches because damage may occur):
NOTE: Refer to Table 13 for motor speed lead relocation if leads
were not identified before disconnection.
17. Reconnect blower leads to furnace control. Refer to fur-
nace wiring diagram, and connect thermostat leads if pre-
viously disconnected.
18. To check blower for proper rotation:
a. Turn on electrical supply.
a. Draft safeguard switch.
b. Inducer motor.
c. Pressure switches.
d. Limit overtemperature switch.
e. Gas valve.
b. Manually close blower access door switch.
f. Hot surface igniter.
g. Flame--sensing electrode
h. Flame rollout switches.
NOTE: If thermostat terminals are jumpered at the time blower
access door switch is closed, blower will run for 90 sec before
beginning a heating or cooling cycle.
6. Remove screws that fasten the collector box assembly to
the cell panel. Be careful not to damage the collector box.
Inducer assembly and elbow need not be removed from
collector box.
c. Perform component self--test as shown at the bottom of
the SERVICE label, located on the front of blower access
door.
d. Verify blower is rotating in the correct direction.
7. Disconnect gas line from gas manifold.
19. If furnace is operating properly, RELEASE BLOWER
ACCESS DOOR SWITCH. Remove any jumpers or re-
connect any disconnected thermostat leads. Replace
blower access door.
8. Remove the 5 screws that attach the burner assembly to
the cell panel. The gas valve and individual burners need
not be removed from support assembly. Remove NOx
baffles if installed.
NOTE: Be very careful when removing burner assembly to
avoid breaking igniter. See Fig. 58 and 59 for correct igniter
location.
!
WARNING
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury, or death.
Blower access door switch opens 115--v power to furnace
control. No component operation can occur unless switch is
closed. Exercise caution to avoid electrical shock from
exposed electrical components when manually closing this
switch for service purposes.
20. Downflow or horizontal furnaces with vent pipe through
furnace only:
a. Install and connect short piece of vent pipe inside furnace
to existing vent.
b. Connect vent connector to vent elbow.
21. Turn on gas supply and cycle furnace through one com-
plete heating and cooling cycle. Verify the furnace temper-
ature rise as shown in Adjustments Section. Adjust tem-
perature rise as shown in Adjustments Section. If outdoor
temperature is below 70_F (21_C) turn off circuit breaker
to outdoor unit before running furnace in the cooling
A05025
Fig. 58 -- Igniter Position--Side View
49
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9. Using field--provided 25--caliber rifle cleaning brush,
36--in. (914 mm) long 1/4--in. (6 mm) diameter steel
spring cable, a variable speed, reversible electric drill, and
vacuum cleaner, clean cells as follows:
1-7/8
(47.6 mm)
a. Remove metal screw fitting from wire brush to allow in-
sertion into cable.
b. Insert the twisted wire end of brush into end of spring
cable, and crimp tight with crimping tool or crimp by
striking with ball--peen hammer. TIGHTNESS IS VERY
IMPORTANT.
NOTE: The materials needed in item 9 can usually be purchased
at local hardware stores.
A05026
Fig. 59 -- Igniter Position--Top View
(1.) Attach variable--speed, reversible drill to the end of
spring cable (end opposite brush).
(2.) Insert brush end of cable into the outlet opening of
cell and slowly rotate with drill. DO NOT force
cable. Gradually insert cable into upper pass of cell.
(See Fig. 60.)
(3.) Work cable in and out of cell 3 or 4 times to obtain
sufficient cleaning. DO NOT pull cable with great
force. Reverse drill and gradually work cable out.
(4.) Insert brush end of cable in burner inlet opening of
cell, and proceed to clean 2 lower passes of cell in
same manner as upper pass.
(5.) Repeat foregoing procedures until each cell in fur-
nace has been cleaned.
A91252
(6.) Using vacuum cleaner, remove residue from each
cell.
Fig. 60 -- Cleaning Heat Exchanger Cell
(7.) Using vacuum cleaner with soft brush attachment,
clean burner assembly.
16. Replace blower access door only, if it was removed.
17. Set thermostat above room temperature and check furnace
for proper operation.
(8.) Clean flame sensor with fine steel wool.
(9.) Install NOx baffles (if removed.)
(10.) Reinstall burner assembly. Center burners in cell
openings.
18. Verify blower airflow and speed changes between heating
and cooling.
10. Remove old sealant from cell panel and collector box
flange.
!
WARNING
FIRE OR EXPLOSION HAZARD
11. Spray releasing agent on the heat exchanger cell panel
where collector box assembly contacts cell panel.
Failure to follow this warning could result in personal injury,
death and/or property damage.
NOTE: A releasing agent such as cooking spray or equivalent
(must not contain corn or canola oil, aromatic or halogenated
hydrocarbons or inadequate seal may occur) and RTV sealant
(G.E. 162, 6702, or Dow--Corning 738) are needed before
starting installation. DO NOT substitute any other type of RTV
sealant. G.E. 162 (P771--9003) is available through RCD in 3--oz.
tubes.
Never use a match or other open flame to check for gas
leaks. Use a soap--and--water solution.
19. Check for gas leaks.
20. Replace outer access door.
12. Apply new sealant to flange of collector box and attach to
cell panel using existing screws, making sure all screws
are secure.
13. Reconnect wires to the following components (Use con-
nection diagram on wiring label, if wires were not marked
for reconnection locations.):
Step 3 — Sequence of Operation
NOTE: Furnace control must be grounded for proper operation
or control will lockout. Control is grounded through green wire
connected to gas valve and burner bracket screw. Using the
schematic diagram in Fig. 57, follow the sequence of operation
through the different modes. Read and follow the wiring diagram
very carefully.
a. Draft safeguard switch.
b. Inducer motor.
c. Pressure switches.
NOTE: If a power interruption occurs during a call for heat
(W/W1 or W/W1--and--W2), the control run the blower for the
selected blower off--delay period two seconds after power is
restored and if the thermostat is still calling for gas heating. The
LED light will flash code 12 during this period, after which the
LED will be ON continuous, as long as no faults are detected.
After this period, the furnace will respond to the thermostat
normally.
d. Limit overtemperature switch.
e. Gas valve.
f. Hot surface igniter.
g. Flame--sensing electrode.
h. Flame rollout switches.
14. Reinstall internal vent pipe, if applicable.
15. Reinstall vent connector on furnace vent elbow. Securely
fasten vent connector to vent elbow with 2 field--supplied,
corrosion--resistant, sheet metal screws located 180_ apart.
The blower door must be installed for power to be conducted
through the blower door interlock switch ILK to the furnace
control CPU, transformer TRAN, inducer motor IDM, blower
motor BLWM, hot--surface igniter HSI, and gas valve GV.
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1. Two--Stage Heating (Adaptive mode) with Single--
Stage Thermostat
d. Flame--Proving--When the burner flame is proved at the
flame--proving sensor electrode FSE, the inducer motor
IDM switches to low--speed unless running at high--
speed, and the furnace control CPU begins the blower--
ON delay period and continues tohold thegas valveGV--
M open. If the burner flame is not proved within two
seconds, the control CPU will close the gas valve GV--M,
and the control CPU will repeat the ignition sequence for
up to three more Trials--For--Ignition before going to Ig-
nition-- Lockout. Lockout will be reset automatically
after three hours, by momentarily interrupting 115 vac
power to the furnace, or by interrupting 24 vac power at
SEC1 or SEC2 to the furnace control CPU (not at W/W1,
G, R, etc.). If flame is proved when flame should not be
present, the furnace control CPU will lock out of Gas--
Heating mode and operate the inducer motor IDM on
high speed until flame is no longer proved.
(See Fig. 23 or 32 for thermostat connections)
NOTE: The low--heat only switch (LHT) selects either the
low--heat only operation mode when ON, (see item 2. below) or
the adaptive heating mode when OFF in response to a call for
heat. (See Fig. 33.) When the W2 thermostat terminal is energized
it will always cause high--heat operation when the R to W circuit
is closed, regardless of the setting of the low--heat only switch.
This furnace can operate as a two--stage furnace with a
single--stage thermostat because the furnace control CPU includes
a programmed adaptive sequence of controlled operation, which
selects low--heat or high--heat operation. This selection is based
upon the stored history of the length of previous gas--heating
periods of the single--stage thermostat.
The furnace will start up in either low-- or high--heat. If the
furnace starts up in low--heat, the control CPU determines the
low--heat on--time (from 0 to 16 minutes) which is permitted
before switching to high--heat.
e. Blower--ON Delay--If the burner flame is proven the
blower--ON delay for low--heat and high--heat are as fol-
lows:
If the power is interrupted, the stored history is erased and the
control CPU will select low--heat for up to 16 minutes and then
switch to high--heat, as long as the thermostat continues to call for
heat. Subsequent selection is based on stored history of the
thermostat cycle times.
Low--Heat--45 seconds after the gas valve GV--M is en-
ergized the blower motor (BLWM) is energized at LO
HEAT speed.
High--Heat--25 seconds after the gas valve GV--M is en-
ergized the BLWM is energized at HI HEAT speed. Sim-
ultaneously, the electronic air cleaner (EAC--1) terminal
is energized and remains energized as long as the BLWM
is energized.
The wall thermostat “calls for heat”, closing the R to W circuit.
The furnace control performs a self--check, verifies the low--heat
and high--heat pressure switch contacts LPS and HPS are open,
and starts the inducer motor IDM in high--speed.
f. SwitchingfromLow--to High--Heat--Ifthe furnacecon-
trol CPU switches from low--heat to high--heat, the fur-
nace control CPU will switch the inducer motor IDM
speed from low to high. The high--heat pressure switch
relay HPSR is de--energized to close the NC contact.
When sufficient pressure is available the high--heat pres-
sure switch HPS closes, and the high--heat gas valve
solenoid GV--HI is energized. The blower motor BLWM
will switch to HI HEAT speed five seconds after the fur-
nace control CPU switches from low--heat to high--heat.
a. Inducer Prepurge Period
(1.) If the furnace control CPU selects low--heat opera-
tion the inducer motor IDM comes up to speed, the
low--heat pressure switch LPS closes, and the fur-
nace control CPU begins a 15--second prepurge
period. After the low--heatpressure switchre--closes
thefurnacecontrolCPUwill begina 15--secondpre-
purge period, and continue to run the inducer motor
IDM at high--speed.
g. Switching from High-- to Low--Heat--The furnace con-
trol CPU will not switch from high--heat to low--heat
whilethethermostat R--to--Wcircuit isclosed when using
a single stage thermostat.
(2.) If the furnace control CPU selects high--heat opera-
tion, the inducer motor IDM remains running at
high--speed, and the high--heatpressure switch relay
HPSR is de--energized to close the NC contact.
When sufficient pressure is available the high--heat
pressure switch HPS closes, and the high--heat gas
valve solenoid GV--HI is energized. The furnace
control CPU begins a 15--second prepurge period
after the low--heat pressure switch LPS closes. If the
high--heat pressure switch HPS fails to close and the
low--heat pressure switch LPS closes, the furnace
will operate at low--heat gas flow rate until thehigh--
heat pressure switch closes for a maximum of 2
minutes after ignition.
h. Blower--OFF Delay--When the thermostatis satisfied, the
R to W circuit is opened, de--energizing the gas valve
GV--M,stoppinggas flowto theburners, andde--energiz-
ing the humidifier terminal HUM. The inducer motor
IDM will remain energized for a 5--second post--purge
period. The blower motor BLWM and air cleaner termin-
al EAC--1 will remain energized for 90, 120, 150, or 180
seconds (depending on selection at blower--OFF delay
switches). The furnace control CPU is factory--set for a
120--second blower--OFF delay.
2. Two--Stage Thermostat and Two--Stage Heating (See Fig.
31 for thermostat connections)
b. Igniter Warm--Up--At the end of the prepurge period,
the (Hot Surface Igniter) HSI is energized for a
17--second igniter warm--up period.
NOTE: In this mode the LHT must be ON to select the low--heat
only operation mode in response to closing the thermostat
R--to--W1 circuit. Closing the thermostat R--to--W1--and--W2
circuits always causes high--heat operation, regardless of the
setting of the low--heat--only switch.
c. Trial--for--Ignition Sequence--When the igniter warm--
up period is completed the main gas valve relay contacts
GVR--1 and --2 close to energize the gas valve solenoid
GV--M,thegas valveopens, and24 vacpower issupplied
for a field--installed humidifier at the HUM terminal. The
gas valve solenoid GV--M permits gas flowto theburners
where it is ignited by the HSI. Five sec after the GVR
closes, a 2--sec flame proving period begins. The HSI ig-
niter will remain energized until the flame issensed orun-
til the 2--sec flame proving period begins. If the furnace
control CPU selects high--heat operation, the high--heat
gas valve solenoid GV--HI is also energized.
The wall thermostat “calls for heat”, closing the R--to--W1 circuit
for low--heat or closing the R--to--W1 and--W2 circuits for
high--heat. The furnace control performs a self--check, verifies the
low--heat and high--heat pressure switch contacts LPS and HPS
are open, and starts the inducer motor IDM in high--speed.
The start up and shut down functions and delays described in
item 1. above apply to the 2--stage heating mode as well, except
for switching from low-- to high--Heat and vice versa.
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a. Switching from Low-- to High--Heat--If the thermostat
R--to-- W1 circuit is closed and the R--to--W2 circuit
closes, the furnace control CPU will switch the inducer
motor IDM speed from low to high. The high--heat pres-
sure switch relay HPSR is de--energized to close the NC
contact. When sufficient pressure is available the high--
heat pressure switch HPS closes, and the high--heat gas
valve solenoid GV--HI is energized. The blower motor
BLWM will switch to HI HEAT speed five seconds after
the R--to--W2 circuit closes.
b. Switching from High-- to Low--Heat--If the thermostat
R--to--W2circuitopens,andtheR--to--W1 circuitremains
closed, the furnace control CPU will switch the inducer
motor IDM speed from high to low. The high--heat pres-
sure switch relay HPSR is energized to open the NC con-
tact and de--energize the high--heat gas valve solenoid
GV--HI. When the inducer motor IDM reduces pressure
sufficiently, the high--heat pressure switch HPS will
open. The gas valve solenoid GV--M will remain ener-
gized as long as the low--heat pressure switch LPS re-
mains closed. The blower motor BLWM will switch to
LO HEAT speed five seconds after the R--to--W2 circuit
opens.
starts the furnace blower motor BLWM at low--cool speed (same
speed as LO HEAT).
If the furnace control CPU switches from low--cooling to
high--cooling, the furnace control CPU will energize the air
conditioning relay ACR. When the air conditioning relay ACR is
energized the R--to--Y1--and--Y2 circuits switch the outdoor unit
to high--cooling speed, and the R--to--G--and--Y1--and--Y/Y2
circuits switch the furnace blower motor BLWM to COOL speed.
NOTE: When transitioning from low--cooling to high--cooling
the outdoor unit compressor will shut down for 1 minute while
the BLWM continues to run at low--cool speed (same speed as
LO--HEAT) until the outdoor unit compressor comes back on at
high speed.
The electronic air cleaner terminal EAC--1 is energized with 115
vac whenever the blower motor BLWM is operating. When the
thermostat is satisfied, the R--to--G--and--Y circuit are opened.
The outdoor unit stops, and the furnace blower BLWM and
electronic air cleaner terminal EAC--1 will remain energized for
an additional 90 seconds. Jumper Y1 to DHUM to reduce the
cooling off--delay to 5 seconds. (See Fig. 34.)
c. Two--Stage Thermostat and Two--Speed Cooling (See
Fig. 31 for thermostat connections)
NOTE: The air conditioning relay disable jumper ACRDJ must
be disconnected to allow thermostat control of the outdoor unit
staging. (See Fig. 33.)
3. Cooling Mode--The thermostat “calls for cooling.”
a. Single--Speed Cooling--
(See Fig. 27 for thermostat connections)
The thermostat closes the R--to--G--and--Y1 circuits for
low--cooling or closes the R--to--G--and--Y1--and--Y2 circuits for
high--cooling. The R--to--Y1 circuit starts the outdoor unit on
low--cooling speed, and the R--to--G--and--Y1 circuit starts the
furnace blower motor BLWM on low--cool speed (same speed as
LO HEAT). The R--to--Y1--and--Y2 circuits start the outdoor unit
on high--cooling speed, and the R--to--G--and-- Y/Y2 circuits start
the furnace blower motor BLWM on COOL speed. The
electronic air cleaner terminal EAC--1 is energized with 115 vac
whenever the blower motor BLWM is operating. When the
The thermostat closes the R--to--G--and--Y circuits. The
R--to-- Y circuit starts the outdoor unit, and the R--to--
G--and--Y/Y2 circuits start the furnace blower motor
BLWM on COOL speed.
The electronic air cleaner terminal EAC--1 is energized
with 115 vacwhen theblower motorBLWM isoperating.
When the thermostat is satisfied, the R--to--G and--Y cir-
cuits are opened. The outdoor unit will stop, and the fur-
nace blower motor BLWMwill continueoperating onthe
COOL speed for an additional 90 seconds. Jumper Y/Y2
to DHUM to reduce the cooling off--delay to 5 seconds.
(See Fig. 24.)
thermostat
is
satisfied,
the
R--to--G--and--Y1
or
R--to--G--and--Y1--and--Y2 circuits are opened. The outdoor unit
stops, and the furnace blower BLWM and electronic air cleaner
terminal EAC--1 will remain energized for an additional 90
seconds. Jumper Y1 to DHUM to reduce the cooling off--delay to
5 seconds. (See Fig. 33.)
b. Single--Stage Thermostat and Two--Speed Cooling
(Adaptive Mode)
(See Fig. 32 for thermostat connections)
4. Thermidistat Mode
This furnace can operate a two--speed cooling unit with
a single--stage thermostat because the furnace control
CPU includes a programmed adaptive sequence of con-
trolled operation, which selects low--cooling or high--
cooling operation. This selection is based upon the stored
history of the length of previous cooling period of the
single--stage thermostat.
(See Fig. 26 -- 28 for Thermidistat connections) The dehu-
midification output, DHUM on the Thermidistat should be
connected to the furnace control thermostat terminal
DHUM. When there is a dehumidify demand, the DHUM
input is activated, which means 24 vac signal is removed
from the DHUM input terminal. In other words, the
DHUM input logic is reversed. The DHUM input is
turned ON when no dehumidify demand exists. Once 24
vac is detected by the furnace control on the DHUM input,
the furnace control operates in Thermidistat mode. If the
DHUM input is low for more than 48 hours, the furnace
control reverts back to non--Thermidistat mode.
NOTE: The air conditioning relay disable jumper ACRDJ must
be connected to enable the adaptive cooling mode in response to
a call for cooling. (See Fig. 33.) When ACRDJ is in place, the
furnace control CPU can turn on the air conditioning relay ACR
to energize the Y/Y2 terminal and switch the outdoor unit to
high--cooling.
The cooling operation described in item 3. above also ap-
plies to operation with a Thermidistat. The exceptions are
listed below:
The furnace control CPU can start up the cooling unit in either
low-- or high--cooling. If starting up in low--cooling, the furnace
control CPU determines the low--cooling on--time (from 0 to 20
minutes) which is permitted before switching to high--cooling. If
the power is interrupted, the stored history is erased and the
furnace control CPU will select low--cooling for up to 20 minutes
and then energize the air conditioning relay ACR to energize the
Y/Y2 terminal and switch the outdoor unit to high--cooling, as
long as the thermostat continues to call for cooling. Subsequent
selection is based on stored history of the thermostat cycle times.
The wall thermostat “calls for cooling”, closing the
R--to--G--and--Y circuits. The R--to--Y1 circuit starts the outdoor
unit on low--cooling speed, and the R--to--G--and--Y1 circuits
a. Low cooling -- When the R--to--G--and--Y1 circuit is
closedandthereisademandfor dehumidification,thefur-
nace blower motor BLWM will continue running at low--
cool speed (same speed as LO HEAT).
b. High cooling --When the R--to--G--and--Y/Y2 circuit is
closedandthereisademandfor dehumidification,thefur-
nace blower motor BLWM will drop the blower speed
from COOL to HI HEAT for a maximum of 10 minutes
before reverting back to COOL speed. If there is still a
demand for dehumidification after 20 minutes, the fur-
52
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nace control CPU will drop the blower speed back to HI
HEAT speed. This alternating 10--minute cycle will con-
tinue as long as there is a call for cooling.
NOTE: If the blower--off delay is set to the maximum, the
adjustable continuous--fan feature is locked (i.e., fan speed cannot
be changed from its current setting).
c. Cooling off--delay -- When the “call for cooling” is satis-
fied and there is a demand for dehumidification, the cool-
ing blower--off delay is decreased from 90 seconds to 5
seconds.
6. Heat Pump
(See Fig. 27 through 30 for thermostat connections)
When installed with a heat pump, the furnace control auto-
matically changes the timing sequence to avoid long
blower off times during demand defrost cycles. When the
R--to-- W/W1--and--Y1 or R--to--W/W1--and--Y1--and--G
circuits are energized the furnace control CPU will switch
to or turn on the blower motor BLWM at low--cool speed
(same speed as LO HEAT), and begin a low--heat cycle.
The blower motor BLWM will remain on until the end of
the prepurge period, then shut off for 24 seconds then
come back on at LO HEAT speed. When the W/W1 input
signal disappears, the furnace control begins a normal in-
ducer post--purge period and the blower remains running
at LO HEAT speed. If the R--to-- W/W1--and--Y1--and--G
signals disappear at the same time, the blower motor
BLWM will remain on for the selected blower-- OFF delay
period. If the R--to--W/W1--and--Y1 signals disappear,
leaving the G signal, the blower motor BLWM will remain
on for the selected blower--OFF delay period then switch
to continuous--blower speed.
When the R--to--W/W1--and--Y/Y2, R--to--W/W1--and--
Y / Y 2 -- a n d -- G , R -- t o -- W / W 1 -- a n d -- Y 1 -- a n d -- Y / Y 2 , o r
R--to--W/W1--and-- Y1--and--Y/Y2--and--G circuits are en-
ergized the furnace control CPU will switch to or turn on
the blower motor BLWM at COOL speed, and begin a
high--heat cycle. The blower motor BLWM will remain on
until the end of the prepurge period, then shut off for 24
seconds then come back on at HI HEAT speed. When the
W/W1 input signal disappears, the furnace control begins
a normal inducer post--purge period and the
5. Continuous Blower Mode
When the R--to--G circuit is closed by the thermostat, the
blower motor BLWM will operate on continuous--blower
speed (can be set to LO HEAT, HI HEAT, or COOL
speed). Factory default is LO HEAT speed. Terminal
EAC--1 is energized as long as the blower motor BLWM is
energized. During a call for heat, the blower BLWM will
stop during igniter warm--up (17 seconds), ignition (7
seconds), and blower--ON delay (45 seconds in low--heat,
and 25 seconds in high--heat), allowing the furnace heat
exchangers to heat up more quickly, then restarts at the
end of the blower--ON delay period at LO HEAT or HI
HEAT speed respectively. The blower motor BLWM will
revert to continuous--blower speed after the heating cycle
is completed. In high--heat, the furnace control CPU will
hold the blower motor BLWM at HI HEAT speed during
the selected blower--OFF delay period before reverting to
continuous--blower speed.
When the thermostat “calls for low--cooling”, the blower
motor BLWM will switch to operate at low--cool speed
(same speed as LO HEAT). When the thermostat is satis-
fied, the blower motor BLWM will operate an additional
90 seconds on low--cool speed before reverting back to
continuous--blower speed.
When the thermostat “calls for high--cooling”, the blower
motor BLWM will operate at COOL speed. When the
thermostat is satisfied, the blower motor BLWM will oper-
ate an additional 90 seconds on COOL speed before re-
verting back to continuous--blower speed.
blower switches to COOL speed after a 3 second delay. If
t h e R -- t o -- W / W 1 -- a n d -- Y / Y 2 -- a n d -- G o r R -- t o -- W / W 1 -- a n d
--Y1--and-- Y/Y2--and--G signals disappear at the same
time, the blower motor BLWM will remain on for the se-
lected blower--OFF delay period. If the R--to--W/W1--
a n d -- Y / Y 2 o r R -- t o -- W / W 1 -- a n d -- Y 1 -- a n d -- Y / Y 2 s i g n a l s
disappear, leaving the G signal, the blower motor BLWM
will remain on for the selected blower-- OFF delay period
then switch to continuous--blower speed.
When the R--to--G circuit is opened, the blower motor
BLWM will continue operating for an additional 5
seconds, if no other function requires blower motor
BLWM operation.
Continuous Blower Speed Selection from Thermostat
To select different continuous--blower speeds from the
room thermostat, momentarily turn off the FAN switch or
push button on the room thermostat for 1--3 seconds after
the blower motor BLWM is operating. The furnace control
CPU will shift the continuous--blower speed from the fact-
ory setting of LO HEAT to HI HEAT speed. Momentarily
turning off the FAN switch again at the thermostat will
shift the continuous--blower speed from HI HEAT to
COOL. Repeating the procedure will shift the continuous--
blower speed from COOL to LO HEAT speed. The selec-
tion can be changed as many times as desired and is stored
in the memory to be automatically used following a power
interruption.
Step 4 — Wiring Diagrams
Refer to wiring diagram, Fig. 57.
Step 5 — Troubleshooting
Refer to the service label. (See Fig. 56—Service Label.) The
Troubleshooting Guide can be a useful tool in isolating furnace
operation problems. Beginning with the word “Start,” answer
each question and follow the appropriate arrow to the next item.
The Guide will help to identify the problem or failed component.
After replacing any component, verify correct operation
sequence.
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A02107A
Fig. 61 -- Troubleshooting Guide -- 2--Speed
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A05001
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Printed in U.S.A.
Edition Date: 11/08
Copyright 2008 Carrier Corp. S 7310 W. Morris St. S Indianapolis, IN 46231
Catalog No:58CT---10SI
Replaces:58CT--9SI
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
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