Thomas Betts Furnace EEDU User Manual

Model EEDU  
and HEEDU  
Indoor/Power-Vented  
Duct Furnaces  
INSTALLATION FORM RGM 421 (Version A)  
APPLIES TO:  
Installation/Operation/Service  
Table of Contents  
Paragraph No.  
Page No.  
Installation and Operation ........................ 1-26.......................... 1-20  
Check Installation and Start-Up .............. 27 ............................. 21  
Service/Maintenance/Troubleshooting ..... 28-33........................ 22-24  
Index by Page Number  
Air Flow Requirements ................................. 13  
Blower Connections ..................................... 14  
Burner Air Adjustment.................................. 21  
Burner Rack Removal .................................. 22  
Burners .......................................................... 21  
Bypass Duct.................................................. 13  
Carryover System ......................................... 21  
Check Installation and Start-Up ................... 21  
CHLORINES .................................................. 5  
Cleaning Pilot and Main Burners................. 22  
Cleaning the Heat Exchanger ....................... 23  
Clearances ...................................................... 4  
Combustion Air ............................................... 4  
Combustion Air Proving Switch .................. 15  
Condensate Drain, Option CS1 .................... 13  
Coupling Two, Three, Four or Five  
Mounting the Furnace .................................... 6  
Pilot and Ignition Systems ........................... 20  
Reversing Air Flow ........................................ 6  
SERVICE ...................................................... 22  
Start-Up ........................................................ 21  
Suspending the Furnace ................................. 6  
Thermostat .................................................... 15  
Troubleshooting ...................................... 23, 24  
Optional Two-Stage Operation..................... 19  
Uncrating ........................................................ 4  
Valve ............................................................. 19  
Venter............................................................ 23  
Venting ........................................................... 9  
Warranty ......................................................... 2  
Wiring Diagrams ..................................... 16-17  
Furnaces ..................................................... 7  
Dimensional Data ........................................... 3  
Disconnect Switch ........................................ 15  
Duct Connections ......................................... 12  
Operating Sequence ...................................... 16  
Optional Ductstat ......................................... 19  
Electrical Supply and Connections .............. 15  
Optional Electronic Modulation .................. 20  
Fan Control (Optional) ................................. 18  
Gas Piping and Pressures ............................... 8  
GENERAL...................................................... 1  
HAZARD INTENSITY LEVELS .................. 2  
Installation Codes ........................................... 2  
Limit Switch ................................................. 17  
MAINTENANCE ......................................... 22  
Reference: Replacement Parts Form, RGM 735  
FOR YOUR SAFETY  
If you smell gas:  
1. Open windows.  
2. Don't touch electrical switches.  
3. Extinguish any open flame.  
4. Immediately call your gas supplier.  
FOR YOUR SAFETY  
The use and storage of gasoline or other  
flammable vapors and liquids in open  
containers in the vicinity of this appliance is  
hazardous.  
WARNING: Gas-fired appliances are not  
designed for use in hazardous atmospheres  
containing flammable vapors or combustible  
dust, in atmospheres containing chlorinated  
or halogenated hydrocarbons, or in  
applications with airborne silicone substances.  
See Hazard Levels, Page 2.  
WARNING: Improper installation, adjustment,  
alteration, service, or maintenance can cause  
property damage, injury or death. Read the  
installation, operation, and maintenance  
instructions thoroughly before installing or  
servicing this equipment.  
GENERAL  
Model  
EEDU  
Characteristics  
Indoor, Power-Vented, Standard CFM, 80%  
Thermal Efficient  
Installation should be done by a qualified agency in accordance  
with the instructions in this manual and in compliance with all  
codes and requirements of authorities having jurisdiction. The  
instructions in this manual apply to the duct furnace models  
shown on the right.  
Indoor, Power-Vented, High CFM, 80%  
Thermal Efficient  
HEEDU  
RGM Form 421, Mfg No. 150492, Page 1  
Download from Www.Somanuals.com. All Manuals Search And Download.  
3. Dimensions  
Figure 1  
C
D
5"  
16"  
K
L
(centerline of hangers)  
(127mm) (406mm)  
F
Electric Supply  
M
6-3/4"  
(171mm)  
H
Limit  
Keep  
clear for  
service  
18"  
(457mm)  
Airflow  
A
29"  
(737mm)  
8-1/8"  
(206mm)  
3-1/2"  
(89mm)  
Combustion  
Air Opening  
4" (102mm)  
Minimum unit  
spacing  
Combustion  
Air Opening  
E
View  
port  
(both  
sides)  
26"  
(660mm)  
J
B
(Duct width)  
G = Gas  
Connection  
(not supply line)  
Front View  
Side View  
Rear View  
K
Dimensions (inches)  
Size  
A
B
C
D
E
F
G
H
J
L
M
Nat Pro  
34-3/8 14-1/4 35-11/16 14-5/8 4-3/8 3-15/16 1/2 1/2  
34-3/8 17 35-11/16 17-3/8 4-3/8 3-15/16 1/2 1/2  
34-3/8 19-3/4 35-11/16 20-1/8 4-3/8 3-15/16 1/2 1/2  
34-3/8 22-1/2 35-11/16 22-7/8 4-3/8 3-15/16 1/2 1/2  
5/8  
5/8  
5/8  
5/8  
12-1/2 7-1/4 7-7/16 4-5/8  
15-1/4 7-1/4 7-7/16  
18 7-1/4 7-7/16 7-3/8  
20-3/4 7-1/4 7-7/16 8-3/4  
75, 100  
125, 140  
170  
6
200  
34-3/8 25-1/4 35-11/16 25-5/8 4-3/8 4-15/16 1/2 1/2 1-3/8 23-1/2 7-1/4 7-7/16 10-1/8  
34-3/8 28 35-11/16 28-3/8 7-1/8 4-15/16 1/2 1/2 1-3/8 26-1/4 7-1/4 7-7/16 11-1/2  
34-3/8 33-1/2 38-1/8 33-7/8 9-7/8 5-15/16 3/4 1/2 1-3/8 31-3/4 9-9/16 7-5/8 13-7/8  
34-3/8 39 38-1/8 39-3/8 12-5/8 5-15/16 3/4 1/2 1-3/8 37-1/4 9-9/16 7-5/8 16-5/8  
34-3/8 44-1/2 38-1/8 44-7/8 15-3/8 5-15/16 3/4 1/2 1-3/8 42-3/4 9-9/16 7-5/8 19-3/8  
225  
250  
300  
350  
400  
Dimensions (mm)  
Size  
A
B
C
D
E
F
G
H
J
K
L
M
Nat Pro  
13 13  
13 13  
13 13  
13 13  
13 13  
13 13  
19 13  
19 13  
19 13  
873  
873  
873  
873  
873  
873  
873  
873  
873  
362  
432  
502  
572  
641  
711  
851  
991  
1130  
906  
906  
906  
906  
906  
906  
968  
968  
968  
371  
441  
511  
581  
651  
721  
860  
1000  
1140  
111  
111  
111  
111  
111  
181  
251  
321  
391  
100  
100  
100  
100  
125  
125  
151  
151  
151  
16  
16  
16  
16  
35  
35  
35  
35  
35  
318  
387  
457  
527  
597  
667  
806  
946  
1086  
184  
184  
184  
184  
184  
184  
243  
243  
243  
189  
189  
189  
189  
189  
189  
194  
194  
194  
117  
152  
187  
222  
257  
292  
352  
422  
492  
75, 100  
125, 140  
170  
200  
225  
250  
300  
350  
400  
RGM Form 421, Mfg No. 150492, Page 3  
Download from Www.Somanuals.com. All Manuals Search And Download.  
4. Uncrating and Preparation  
5. Location, Clearances, and  
Combustion Air  
This furnace was test operated and inspected at the factory prior to  
crating and was in operating condition. If the furnace has incurred any  
damage in shipment, file a claim with the transporting agency.  
Unit must be installed so that the following clearances are provided for  
combustion air space, service and inspection, and for proper spacing  
from combustible construction.  
CAUTION: Remove the panel from the bottom rear of the  
furnace (See Paragraph 28) and check the burner rack as-  
sembly. The burner rack "drawer" should be setting level with  
each side on a support rail. Check to assure that EXCES-  
SIVE shipping vibration has not caused the burner rack as-  
sembly to "drop off" the support rails into the bottom pan. If  
the burner rack assembly is positioned properly, close the  
back panel. If the burner rack has fallen, remove the screws  
holding the burner rack assembly and pull out the burner rack  
"drawer". Re-assemble by sliding the burner rack "drawer"  
into the heater, being sure that both sides are resting on the  
support rails. Re-attach to the support brackets underneath  
the burners. Re-insert the burner rack screws and close the  
back panel.  
NOTE: See Figure 5 for service clearance illustration.  
REQUIRED CLEARANCES  
Front Top Flue Connector Sides Bottom Rear  
6"  
6"  
6"  
6"  
12"  
29"  
152mm 152mm  
152mm  
152mm 305mm 737mm  
CAUTION: Do not locate heater where it may  
be exposed to liquid spray, rain or dripping  
water.  
These duct furnaces are designed to take combustion air from the space  
in which the furnace is installed. The air that enters into the combus-  
tion process is vented to the outdoors. Sufficient air must enter the  
equipment location to replace the air exhausted through the vent sys-  
tem. Modern construction methods involve the greater use of insula-  
tion, improved vapor barriers and weather-stripping, with the result  
that buildings generally are much tighter structurally than they have  
been in the past. The combustion air supply for gas-fired equipment  
can be affected by these construction conditions because infiltration  
that would have existed in the past may not be adequate. Extensive use  
of exhaust fans aggravates the situation. In the past the filtration of  
outside air assumed in heat loss calculations (one air change per hour)  
was assumed to be sufficient. However, current construction methods  
may now require the introduction of outside air through wall openings  
or ducts.  
Check the rating plate for the gas specifications and electrical charac-  
teristics of the furnace to be sure that they are compatible with the gas  
and electric supplies at the installation site. Read this booklet and be-  
come familiar with the installation requirements of your particular fur-  
nace. If you do not have knowledge of local requirements, check with  
the local gas company or any other local agencies who might have  
requirements concerning this installation. Before beginning, make  
preparations for necessary supplies, tools, and manpower.  
Check to see if there are any field-installed options that need to be  
assembled to the furnace prior to installation.  
Option Parts -- Some gas control options will have parts either shipped  
loose with the heater or shipped separately. If your unit is equipped  
with any of the following gas control options, be sure these parts are  
available at the job site.  
WARNING: These furnaces are designed to take  
combustion air from the space in which the unit  
is installed and are not designed for connection  
to outside combustion air intake ducts. Use of  
outside air ducts voids the warranty and could  
cause hazardous operation. (See Hazard Levels,  
page 2.)  
Heating -- Gas Option AG7  
Control Option Amplifier, P/N 48035  
Thermostat, P/N 48033  
Makeup Air -- Option AG3  
Gas Control  
Options  
Control Switch, P/N 29054  
Gasket, P/N 7726  
Requirements for combustion air and ventilation air depend upon  
whether the unit is located in a confined or unconfined space. An "un-  
confined space" is defined as a space whose volume is not less than 50  
cubic feet per 1000 BTUH of the installed appliance. Under all condi-  
tions, enough air must be provided to ensure there will not be a nega-  
tive pressure condition within the equipment room or space. A posi-  
tive seal must be made in all return-air connections and ducts. Even a  
slight leak can create a negative pressure condition in a confined space  
and affect combustion.  
Gasket Retainer Plate, P/N 7727  
Option AG8  
Temperature Sensor, P/N 48041  
Amplifier, P/N 48037  
Control Switch, P/N 29054  
Option AG9  
Remote Temperature Selector, P/N 48042  
Temperature Sensor, P/N 48041  
Amplifier, P/N 48035  
(All of these  
options also  
require a  
shipped-  
separate fan  
control, Opt  
CQ1 (P/N  
57960), which  
should be  
at the job  
site.  
Installation in a Confined Space  
Control Switch, P/N 29054  
Option AG15 or AG16  
Figure 2 -  
Confined Space: A  
space whose volume  
is less than 50 cubic  
feet per 1000 BTUH  
of the installed  
appliance input  
rating  
Remote Temperature Selector, P/N 115848  
Stage Adder M odule, P/N 115849  
Control Switch, P/N 29054  
Transformer 115 to 24V, P/N 103055 or  
208/230 to 24V, P/N 103497; and 1/2" locknut,  
P/N 16222 (for transformer)  
Display M odule, P/N 115852 (AG16 only)  
Do not install a unit in a confined space without providing wall open-  
ings leading to and from the space. Provide openings near the floor  
and ceiling for ventilation and air for combustion as shown in Figure  
Other shipped-separate options could include a gas shutoff valve, a  
condensate drain fitting, a thermostat, a hanger kit, a coupling kit, a fan  
control, or high temperature sealing tape.  
Form 421, Page 4  
Download from Www.Somanuals.com. All Manuals Search And Download.  
2, depending on the combustion air source as noted in Items 1, 2, and  
3 below the illustration.  
Figure 3A - Limit Control Location - When reversing  
air flow, the limit control must be re-located. The  
limit control MUST be on the discharge end of the  
heat exchanger  
Add total BTUH of all appliances in the confined space and divide by  
figures below for square inch free area size of each (top and bottom)  
opening.  
1. Air from inside the building -- openings 1 square inch free area per  
1000 BTUH. Never less than 100 square inches free area for each open-  
ing. See (1) in Figure 2.  
2. Air from outside through duct -- openings 1 square inch free area  
per 2000 BTUH. See (2) in Figure 2.  
3. Air direct from outside -- openings 1 square inch free area per 4000  
BTUH. See (3) in Figure 2.  
NOTE: For further details on supplying combustion air to a confined  
space, see the National Fuel Gas Code ANSI Z223.1a (latest edition ).  
Location of  
the  
factory-  
installed  
Limit  
Control  
Bracket on  
a Furnace  
with  
Hazards of Chlorines  
The presence of chlorine vapors in the combustion air of gas-fired heat-  
ing equipment presents a potential corrosion hazard. Chlorine will,  
when exposed to flame, precipitate from the compound, usually freon  
or degreaser vapors, and go into solution with any condensation that is  
present in the heat exchanger or associated parts. The result is hydro-  
chloric acid which readily attacks all metals including 300 grade stain-  
less steel.  
Standard  
Air Flow  
Direction  
Care should be taken to separate these vapors from the combustion  
process. This may be done by wise location of the furnace with regard  
to exhausters or prevailing wind direction. Remember, chlorine is  
heavier than air. This fact should be kept in mind when determining  
installation locations of heating equipment and building exhaust sys-  
tems.  
NOTE: Actual gas valve  
may not be as illustrated.  
Figure 3B - Model EEDU has a top and bottom  
support assembly and individual baffles.  
6. Instructions for Reversing Air Flow  
by Changing Directional Air Baffles  
in the Heat Exchanger  
Duct furnaces are equipped with directional air baffles between the  
heat exchanger tubes. Facing the control compartment of the furnace,  
the standard direction of air flow is from the rear of the furnace (gas  
valve location) toward the front of the furnace. If the installation site  
requires air flow from the front to the rear, the unit may be field adapted  
by re-locating the limit control and reversing the position of the direc-  
tional air baffles.  
Instructions:  
NOTE: If the unit has optional outer side panels, locate the limit con-  
trol and remove the outer panel on that side of the furnace.  
1. All Models - Refer to Figure 3A. Remove the screws attaching the  
limit control bracket to the side of the furnace. Carefully pull the bracket/  
control assembly through the hole. (Do not disconnect wires.)  
2. All EEDU Models (see below for high CFM HEEDU Models) -  
Refer to Figure 3B and follow Steps a)-d) below to reverse the direc-  
tion of the baffles.  
a) Remove Screws "A". Individually lift each baffle slightly and slide  
forward. Remove all baffles completely from the heat exchanger.  
All HEEDU Models (see above for EEDU Models) - Refer to  
Figure 3C and follow Steps a) and b) below to move the top  
baffle to the entering air end of the heater exchanger.  
a) Remove screws B and the baffle.  
b) Re-position the baffle on the "entering air" end of the heat exchanger  
and attach.  
b) Remove Screws B and the top baffle support assembly. Re-position  
the assembly on the opposite send of the heat exchanger and attach.  
c) Remove Screws C and the assembled bottom baffle support and  
brackets. Plug the holes in the heat exchanger bottom by re-insert-  
ing the screws in the holes. Position the assembly on the opposite  
end of the heat exchanger and attach using field-supplied sheet metal  
screws.  
d) Re-install all of the individual baffles by reversing procedure in  
Step a) above.  
RGM Form 421, Mfg No. 150492, Page 5  
Download from Www.Somanuals.com. All Manuals Search And Download.  
Figure 4A - Suspending a Single Furnace  
6. Instructions for Reversing Air  
Flow (cont'd)  
Figure 3C - Model  
as only a  
ear heat  
r baffle.  
)  
her  
Centerline of hangers  
A
350  
400  
3. All Models - Relocate the limit control.  
39-3/8" 1000mm  
44-7/8" 1140mm  
a) At the discharge end on the same side of the heat exchanger, mea-  
sure down 4-1/2" and in 1-11/16". Using that point as the center,  
punch a 2-1/4" diameter hole in the side panel.  
NOTE: It may be necessary to move cable connections. Re-insert  
screws to plug all holes in the side panel. After the limit control is  
installed, the cable connections may be re-attached using field-sup-  
plied sheet metal screws.  
Figure 4B - Option  
CK3 Hanger Kit (P/N  
57959) with four  
Free-turning  
threaded  
socket  
b) With the limit control on the heat exchanger side of the bracket,  
slide the limit control/bracket assembly into the hole. Attach the  
bracket with two sheet metal screws.  
threaded sockets  
(1" pipe)  
c) Cover all of the original factory-made limit control holes with a  
field-supplied sheet metal plate. Do not leave any open holes in the  
side panel or the heat exchanger bottom.  
4. The furnace is now ready for installation with the air flow from front  
to rear (gas valve side).  
Mounting the Furnace  
Change position of the hanger bracket as shown in Figure 5. When the  
furnace is mounted on combustible material, a minimum clearance of  
12" is required.  
7. Suspending or Mounting the  
Furnace  
Before installing the furnace, check the supporting structure to be used  
to verify that it has sufficient load-carrying capacity to support the weight  
of the unit.  
Figure 5 - Base Mounted Furnace  
As shipped location of hanger  
support angle  
Net Weight  
Size 75 100 125 140 170 200 225 250 300 350 400  
Limit  
Lbs 104 104 126 128 150 172 194 216 262 306 328  
Control  
Suspending the Furnace  
Airflow  
Direction  
The furnace is provided with four 15/32" diameter holes to provide  
four-point suspension. To suspend the unit, cut lengths of 7/16"-16  
threaded rod to provide unit height. See Figure 4A for details. NOTE:  
A hanger adapter kit Option CK3 is available to facilitate suspension.  
See Figure 4B.  
Access  
Panel  
Access  
Panel  
10"  
(254  
mm)  
Combustion  
Air Inlet  
Combustion Air Inlet  
Keep clean and maintain 29"  
(737mm) clearance for burner  
rack service  
6" (152mm)  
minimum  
clearance  
6"  
WARNING: Units must be level for proper  
operation. Do not place or add additional weight  
to the suspended furnace. See Hazard Levels,  
page 2.  
12" (305mm)  
Hanger Support Angle  
Form 421, Page 6  
Download from Www.Somanuals.com. All Manuals Search And Download.  
8. Coupling Two, Three, Four or Five Furnaces using Optional Coupling Kits  
Refer to illustrations and follow the instructions below.  
Figure 6B - Installing Coupling Kit  
Coupling Kit, Option CR1 (P/N  
57963), for Two Furnaces  
Qty P/N Description  
Tie Plate  
4"  
1
2
1
2
57964 Filler Plate  
2
57965 Tie Plate  
9557 Threaded Socket Assembly  
3
2
2
5095 3/8-16 x 1-1/4" lg Hex  
Head Bolts  
5197 Split Ring Lock Washer  
Unit  
2
6
Unit  
1
5
20 11813 #10 x 1/2" lg Sheetmetal  
Screws  
7
7
Additional Kits:  
3 Furnaces - Option CR2 (P/N 82654)  
4 Furnaces - Option CR3 (P/N 82655)  
5 Furnaces - Option CR4 (P/N 82656)  
Item  
Description  
Socket Assembly  
Bolt  
1
2
3
5
6
7
Lockwasher  
Spotweld Nut  
Tie Plate  
Figure 6A - Coupling Furnaces  
Hanger Angles  
Instructions for Coupling Furnaces (Refer to Figures 6A,  
6B, 6C and 6D)  
1. Attach the tie plate to the first furnace using threaded socket assem-  
blies. Tie plate must be positioned below the hanger angles. Secure  
fasteners firmly.  
2. Move the second furnace into position next to the first furnace. Tie  
plate must be below the hanger angle. Secure the tie plate to the  
hanger angle using the 3/8-16 bolts, the washers, and the spotweld  
nuts on the tie plate.  
3. Position the filler plates to furnaces as shown in Figure 6A. Using a  
filler plate as a template, drill 1/8" diameter holes. Attach filler plates  
using the sheet metal screws provided. Offset of filler plate allows  
alignment with unit duct flanges. See Figure 6C.  
4. Coupled units require access panels in the top or bottom of the  
outlet duct for limit control service. See Figure 6D and Paragraph  
11.  
Figure 6C - Front View of Coupled Furnaces  
Figure 6D - Top View of Coupled Furnaces (NOTE:  
Access panel may be in top or bottom of ductwork.)  
A + 2"  
(51mm)  
A
Limit  
Control  
Limit  
Limit Control  
Control  
Access panel for  
limit control  
service and  
observation of  
coupled unit  
Discharge Duct  
Size  
"A"  
14-5/8"  
75-100  
371mm  
371mm  
371mm  
371mm  
371mm  
371mm  
860mm  
125-140 17-3/8"  
170  
200  
225  
250  
300  
350  
400  
20-1/8"  
22-7/8"  
25-5/8"  
28-3/8"  
33-7/8"  
39-3/8" 1000mm  
44-7/8" 1140mm  
RGM Form 421, Mfg No. 150492, Page 7  
Download from Www.Somanuals.com. All Manuals Search And Download.  
9. Gas Piping and Pressures  
WARNING: This appliance is equipped for a  
maximum gas supply pressure of 1/2 pound, 8  
ounces, or 14 inches water column. Supply  
pressure higher than 1/2 pound requires  
installation of an additional service regulator  
external to the unit.  
PRESSURE TESTING SUPPLY PIPING  
Test Pressures Above 1/2 PSI: Disconnect the heater and manual valve  
from the gas supply line which is to be tested. Cap or plug the supply  
line.  
NOTE: To permit  
burner removal,  
this nipple must  
extend beyond  
edge of heater.  
Test Pressures Below 1/2 PSI: Before testing, close the manual valve  
on the heater.  
All piping must be in accordance with requirements outlined in the  
National Fuel Gas Code ANSI/Z223.1a (latest edition), published by  
the American Gas Association or CAN/CGA-B149.1 and B149.2, pub-  
lished by the Canadian Gas Association (See Paragraph 1). Gas supply  
piping installation should conform with good practice and with local  
codes.  
Figure 7 - Supply Piping Connection  
with a minimum 3" drip leg. Local codes may require a minimum drip  
leg longer than 3" (typically 6").  
Gas connection sizes are included in the Dimensional Tables in Para-  
graph 3. After all connections are made, disconnect the pilot supply at  
the control valve and bleed the system of air. Reconnect the pilot line  
and leak-test all connections by brushing on a soap solution.  
Duct furnaces for natural gas are orificed for operation with gas having  
a heating value of 1000 (+ or - 50) BTUH per cubic ft. If the gas at the  
installation does not meet this specification, consult the factory for  
proper orificing.  
Gas Connection to Single-Stage Valve  
(Not Gas Supply Line Size)  
Pipe joint compounds (pipe dope) shall be resistant to the action of  
liquefied petroleum gas or any other chemical constituents of the  
gas being supplied.  
Unit Size  
75-250  
300-400  
Natural Gas  
Propane Gas  
1/2"  
1/2"  
3/4"  
1/2"  
WARNING: All components of a gas supply  
system must be leak tested prior to placing  
equipment in service. NEVER TEST FOR  
LEAKS WITH AN OPEN FLAME. Failure to  
comply could result in personal injury, property  
damage or death.  
Install a ground joint union and manual shut-off valve upstream of the  
unit control system, as shown in Figure 7. The 1/8" plugged tapping in  
the shut-off valve provides connection for supply line pressure test  
gauge. The National Fuel Gas Code requires the installation of a trap  
Manifold or Orifice Pressure Settings  
Measuring manifold gas pressure cannot be done until the heater is in  
operation. It is included in the steps of the "Check-Test-Start" proce-  
dure in Paragraph 24. The following warnings and instructions apply.  
WARNING: Manifold gas pressure must never  
exceed 3.5" w.c. for natural gas and 10" w.c. for  
propane gas.  
Capacity of Piping  
Cubic Feet p er Hour based on 0.3" w.c. Pressure Drop  
Sp ecific Gravity for Natural Gas -- 0.6 (Natural Gas -- 1000 BT U /Cubic Ft)  
Sp ecific Gravity for Prop ane Gas -- 1.6 (Prop ane G as -- 2550 BT U/Cubic Ft)  
Length  
of  
Diameter of Pipe  
1/2"  
3/4"  
1"  
1-1/4"  
1-1/2"  
2"  
Pipe Natural Propane Natural Propane Natural Propane Natural Propane Natural Propane Natural Propane  
20'  
30'  
40'  
50'  
60'  
70'  
80'  
90'  
100'  
125'  
150'  
175'  
200'  
92  
73  
63  
56  
50  
46  
43  
40  
38  
34  
31  
28  
26  
56  
45  
38  
34  
31  
28  
26  
24  
23  
21  
19  
17  
16  
190  
152  
130  
115  
105  
96  
90  
84  
79  
72  
116  
93  
79  
70  
64  
59  
55  
51  
48  
44  
39  
36  
34  
350  
285  
245  
215  
195  
180  
170  
160  
150  
130  
120  
110  
100  
214  
174  
149  
131  
119  
110  
104  
98  
92  
79  
73  
67  
730  
590  
500  
440  
400  
370  
350  
320  
305  
275  
250  
225  
210  
445  
360  
305  
268  
244  
226  
214  
195  
186  
168  
153  
137  
128  
1100  
890  
760  
670  
610  
560  
530  
490  
460  
410  
380  
350  
320  
671  
543  
464  
409  
372  
342  
323  
299  
281  
250  
232  
214  
195  
2100  
1650  
1450  
1270  
1105  
1050  
990  
930  
870  
780  
710  
1281  
1007  
885  
775  
674  
641  
604  
567  
531  
476  
433  
397  
372  
64  
59  
55  
650  
610  
61  
Note: When sizing sup p ly lines, consider p ossibilities of future exp ansion and increased requirements.  
Refer to National Fuel Gas Code for additional information on line sizing.  
Form 421, Page 8  
Download from Www.Somanuals.com. All Manuals Search And Download.  
For Natural Gas: Manifold gas pressure is regulated by  
the combination valve to 3.5" w.c. Inlet pressure to the valve  
must be a minimum of 5" w.c. or as noted on the rating  
plate and a maximum of 14" w.c.  
Instructions for Checking Manifold Pressure:  
1) With the manual valve (on the combination valve) positioned to prevent flow to  
the main burners, connect a manometer to the 1/8" pipe outlet pressure tap in the  
valve. NOTE: A manometer (fluid-filled gauge) is recommended rather than a  
spring type gauge due to the difficulty of maintaining calibration of a spring type  
gauge.  
For Propane Gas: Manifold gas pressure is regulated by  
the combination valve to 10" w.c. Inlet pressure to the valve  
must be a minimum of 11" w.c. and a maximum of 14" w.c.  
2) Open the valve and operate the heater. Measure the gas pressure to the mani-  
fold. Normally adjustments should not be necessary to the factory preset regulator.  
Before attempting to measure or adjust manifold gas pres-  
sure, the inlet (supply) pressure must be within the speci-  
fied range for the gas being used both when the heater is in  
operation and on standby. Incorrect inlet pressure could  
cause excessive manifold gas pressure immediately or at  
some future time.  
If adjustment is necessary, set pressure to correct settings by turning the regulator  
screw IN (clockwise) to increase pressure. Turn regulator screw OUT (counter-  
clockwise) to decrease pressure.  
Consult the valve manufacturer's literature provided with the furnace for more  
detailed information.  
10. Venting  
WARNING: Failure to provide proper venting  
could result in death, serious injury, and /or  
property damage. Unit must be installed with a  
flue connection and proper vent to the outside of  
the building. Follow installation codes listed in  
Paragraph 1 and all venting instructions. Safe  
operation of any gas-fired equipment requires a  
properly operating vent system, correct provision  
for combustion air (See Paragraph 5) and regular  
maintenance and inspection. See Hazard Levels,  
page 2.  
WARNING: Units installed in multiples require  
individual vent pipe runs and vent caps.  
Manifolding of vent runs is not permitted due to  
possible recirculation of combustion products  
into the building and possible back pressure  
effects on the combustion air proving switch.  
Comply with the specific requirements and instructions in the follow-  
ing paragraphs.  
Specific Venting Requirements (read all before installing)  
1. Venter (Flue) Outlet  
Venter Outlet  
Diameter  
Size  
Venting must be in accordance with the National Fuel Gas Code Z223.1  
or CAN/CGA B149.1 and B149.2, Installation Code for Gas Burning  
Appliances and Equipment, and all local codes. Local requirements  
supersede national requirements.  
75 - 200  
225 - 250  
300 - 400  
4"  
5"  
6"  
These power-vented units are designed to operate safely and efficiently  
with either a horizontal or vertical vent. (Horizontal vent run is recom-  
mended for maximum fuel savings.) Use either vent pipe approved for  
a Category III heater or appropriately sealed single-wall pipe. Or, if at  
least half of the equivalent length of the vent system is vertical, vent  
pipe approved for a Category I heater may be used. A vent cap of a type  
approved for use with this heater is required. If a vent cap is shipped  
with the heater, it is packaged attached to the venter housing. Detach  
the vent cap from the housing.  
Venter Outlet Attachment Requirements:  
o If the pipe used in the vent run is larger than the diameter of the  
venter outlet (See Vent Length Table 2), make the transition at the  
venter outlet.  
o The venter is factory-installed as illustrated in Figure 8A. If re-  
quired, the venter housing may be rotated as shown in Figure 8B.  
The vent may be run in either of the three directions as indicated by  
1, 2, and 3 in the illustrations. Follow the instructions to rotate the  
venter housing.  
Figure 8A - Factory-Installed Position of the Venter  
Housing  
Instructions for Rotating Venter Housing  
Figure 8B -  
1. Remove the three screws that attach the venter  
Alternate  
housing to the outlet duct (pipe from furnace  
to the venter). The assembly will remain in  
Position of  
the Venter  
place.  
Housing  
2. Remove the three screws holding the motor  
plate to the venter housing. Holding the motor,  
rotate the venter housing to the alternate posi-  
tion (Figure 8B). Re-attach the motor plate to  
the housing. (To ensure correct venter wheel  
alignment, pre-punched holes are provided in  
the motor plate.)  
3. Using the holes in the venter housing as a tem-  
WARNING: Only the venter housing may be rotated. The  
motor and combustion air proving switch MUST remain as  
received from the factory. Unsafe or improper operation will  
result if the standard position is varied. See Paragraph 16 for  
explanation of combustion air proving switch.  
plate, drill three 1/8" diameter holes in the out-  
let duct. Re-attach the venter housing to the  
outlet duct using the three screws removed in  
Step 1. Rotation is complete.  
RGM Form 421, Mfg No. 150492, Page 9  
Download from Www.Somanuals.com. All Manuals Search And Download.  
4. Vent System Joints - Vent system joints depend on the installa-  
tion and the type of pipe being used.  
10. Venting (cont'd)  
Specific Venting Requirements (read all before installing) (cont'd)  
If installed as a Category III heater (required if more than half of  
the equivalent length of the vent system is horizontal) and single-  
wall vent pipe is being used, use at least two non-corrosive screws  
per vent pipe joint and seal all joints to prevent leakage of flue  
gases into the building. For sealing joints, the use of Aluminum or  
TEFLON® (trademark of DuPont Corporation) tape suitable for  
550oF is recommended (required in California). Vent tape of this  
type is available from the heater manufacturer as P/N 98266.  
If installed as a Category III heater (required if more than half of  
the equivalent length of the vent system is horizontal) and vent  
pipe specifically approved for Category III vent systems is be-  
ing used, follow the pipe manufacturer's instructions for proper  
sealing.  
If installed with a Category I vent system (allowed only if at  
least half of the equivalent length of the vent system is vertical),  
use at least two non-corrosive screws per vent pipe joint on single-  
wall pipe or follow the pipe manufacturer's instructions for joining  
double-wall pipe.  
5. Vent System Support - Support lateral runs every six feet, us-  
ing a non-combustible material such as strap steel or chain. Do not  
rely on the heater for support of either horizontal or vertical vent  
pipe.  
1. Venter (Flue) Outlet (cont'd)  
Venter Outlet Attachment Requirements (cont'd):  
o A minimum of 12" of straight pipe is required at the venter outlet  
(or transition fitting) before installing an elbow in the vent system.  
An elbow should never be attached directly to the venter.  
2. Vent Pipe  
If installed with a horizontal vent run, use either vent pipe approved  
for a Category III heater or appropriately sealed 26-gauge galvanized  
steel or equivalent single-wall pipe. If at least half of the equivalent  
length of the vent system is vertical, vent pipe approved for a Category  
I heater may be used. Single-wall pipe or double-wall (Type B) vent  
pipe are suitable for use with a Category I heater.  
Use only one of the flue pipe diameters listed in the Vent Length Tables  
for the furnace size being installed.  
3. Vent Length Tables  
Table 1: Maximum Permissible Vent Lengths with  
S tandard Vent Pipe Diameters  
Vent Pipe  
Size Diameter  
(inches)  
Maximum  
Vent Length  
Equivalent Straight  
Length* - ft (M)  
90O El bo w 4 5 O El bo w  
(see Note 1 below)  
40 ft (12.2 M)  
50 ft (15.2 M)  
50 ft (15.2 M)  
50 ft (15.2 M)  
50 ft (15.2 M)  
50 ft (15.2 M)  
50 ft (15.2 M)  
50 ft (15.2 M)  
50 ft (15.2 M)  
50 ft (15.2 M)  
50 ft (15.2 M)  
75  
4
4
4
4
4
4
5
5
6
6
6
6 (1.8)  
7 (2.1)  
7 (2.1)  
7 (2.1)  
7 (2.1)  
7 (2.1)  
9 (2.7)  
9 (2.7)  
3 (.9)  
6. Condensation - Single wall vent pipe exposed to cold air or run  
through unheated areas must be insulated. Where extreme conditions  
are anticipated, install a means of condensate disposal.  
100  
125  
140  
170  
200  
225  
250  
300  
350  
400  
3.5 (1.1)  
3.5 (1.1)  
3.5 (1.1)  
3.5 (1.1)  
3.5 (1.1)  
4.5 (1.4)  
4.5 (1.4)  
7. Vent Terminal (Pipe and Vent Cap) - The vent system must be  
terminated with a suitable vent cap that is the same size as the vent run.  
Heaters with an A.G.A. rating plate that are ordered with an optional  
vent cap and all heaters with a C.G.A. rating plate have a vent cap  
packaged with the heater. If the "standard" size (Vent Length Table 1)  
of vent pipe is used, install the vent cap provided. If a vent cap is not  
included or if a non-standard size (Vent Length Table 2) of vent pipe is  
used, a field-provided cap must be used. If the vent cap is field-sup-  
plied, use a Type L Breidert Air-x-hauster® or equivalent vent cap.  
(Type L Air-x-hauster® is a trademark of The G. C. Breidert Com-  
pany.) Use of a vent cap supplied by the pipe manufacturer is not  
permitted; the vent cap must be the type approved for use with this  
heater. A different style vent cap could cause nuisance problems or  
unsafe conditions.  
11 (3.4) 5.5 (1.7)  
11 (3.4) 5.5 (1.7)  
11 (3.4) 5.5 (1.7)  
*Reduce the maximumvent length by the amount indicated  
for each elbow used.  
Table 2: Optional Maximum Permissible Vent Lengths  
(Requires an increase in vent pipe diameter.)  
See the illustrations in Figures 9 and 10 for requirements of both verti-  
cal and horizontal vent termination. The vent terminal section may be  
either single-wall or double-wall (Type B) vent pipe.  
Vent Pipe  
Size Diameter  
(inches)  
Maximum  
Vent Length  
Equivalent Straight  
Length* - ft (M)  
90O El bo w 4 5 O El bo w  
(see Note 1 below)  
60 ft (18.3 M)  
70 ft (21.3 M)  
70 ft (21.3 M)  
70 ft (21.3 M)  
70 ft (21.3 M)  
80 ft (24.3 M)  
90 ft (27.4 M)  
If double-wall pipe is used in the vent terminal, follow the instructions  
below to attach the vent cap and to connect the double-wall pipe to the  
single-wall vent pipe run.  
170  
200  
225  
250  
300  
350  
400  
5
5
6
6
7
7
7
9 (2.7)  
9 (2.7)  
4.5 (1.4)  
4.5 (1.4)  
11 (3.4) 5.5 (1.7)  
12 (3.7) 6 (1.8)  
INSTRUCTIONS FOR DOUBLE WALL PIPE INSTALLA-  
TION: Material Required: Double wall (Type B) Vent Pipe (Note:  
Using only one piece of vent pipe is recommended.); a thimble de-  
signed for double wall pipe (if construction is combustible); six  
3/4" long sheetmetal screws; the vent cap; and a tube of silicone  
sealant  
13 (4.0) 6.5 (2.0)  
13 (4.0) 6.5 (2.0)  
14 (4.3)  
7 (2.1)  
Instructions to attach VENT CAP to DOUBLE WALL (Type B)  
VENT TERMINAL  
Look for the "flow" arrow on the vent pipe. Attach the vent cap to  
the "exhaust" end of the double wall pipe.  
*Reduce the maximumvent length by the amount indicated  
for each elbow used.  
NOTE 1: If the system contains all vertical pipe or a combination  
of vertical and horizontal vent pipe, the Maximum Permissible Vent  
Length shown in Tables 1 and 2 may be increased one foot for each  
foot of vertical pipe, up to a maximum increase of 10 feet for Model  
Sizes 75 - 125 and up to 20 feet for Model Sizes 140 - 400.  
1) Slide the vent cap inside the pipe.  
2) Drill a hole through the pipe and the vent cap. (Hole should be  
slightly smaller than the sheet metal screw being used.) Using a  
3/4" long sheet metal screw, attach the cap to the pipe.  
3) Repeat Step 2) drilling and inserting two additional screws evenly  
spaced (120° apart) around the pipe.  
Form 421, Page 10  
Download from Www.Somanuals.com. All Manuals Search And Download.  
Instructions to connect the SINGLE WALL VENT system to a  
DOUBLE WALL (Type B) VENT TERMINAL:  
3) Repeat Step 2) drilling and inserting two additional screws evenly  
spaced (120° apart).  
1) Slide the single wall pipe inside the inner wall of the double-wall  
terminal pipe.  
2) Drill a hole through both walls of the double wall pipe and the  
single wall pipe. (Hole should be slightly smaller than the sheet  
metal screws being used .) Using a 3/4" long sheet metal screw,  
attach the two pieces of pipe. Do not overtighten.  
4) To seal the annular opening (the gap between the single and double  
wall pipe), run a large bead of silicone sealant in the opening. The  
bead of sealant must be large enough to seal the opening, but it is  
not necessary to fill the full volume of the annular area.  
Figu
Vert
Ven
Term
Figure 10 -  
Horizontal  
Vent  
Terminal  
Horizontal Vent Terminal Clearances  
Minimum Clearances for Vent Termination  
Location (all directions unless specified)  
3 ft (0.9m) above  
The location of the termination of the hori-  
zontal vent system must be in accordance with  
National Fuel Gas Code Z223.1. See table for  
required minimum clearances.  
Structure  
Forced air inlet within 10 ft (3.1m)  
Combustion air inlet of another appliance  
6 ft (1.8m)  
If the vent terminal is to be installed near  
ground level, position it at least six inches  
above maximum anticipated snow depth.  
NOTE: Maintain the required clearance  
from the wall to the vent terminal cap for  
stability under wind conditions and to pro-  
tect the building.  
Door, window or gravity air inlet (any building 4 ft (1.2m) horizontally  
opening)  
4 ft (1.2m) below  
3 ft (0.9m) above  
Electric meter, gas meter * and relief equipment 4 ft (1.2m) horizontally  
Gas regulator *  
3 ft (0.9m)  
Adjoining building or parapet  
Grade (ground level)  
6 ft (1.8m)  
7 ft (2.1m) above  
*Do not terminate the vent directly above a gas meter or service regulator.  
RGM Form 421, Mfg No. 150492, Page 11  
Download from Www.Somanuals.com. All Manuals Search And Download.  
11. Duct Connections  
Figure 12A - Connecting Ductwork to the Furnace  
1
Flanges on the heater turn out as shown.  
Shape duct connection as shown -- "U" on top and bottom;  
"L" on sides.  
Figure 11 - Duct  
Connection Dimensions  
(inches)  
2
3
4
Slide "U" form over heater flange making connection.  
Form "U" strips to seal ends. Drill and lock with sheetmetal  
screws.  
Size  
75, 100  
125, 140  
170  
G
12-1/2" 318  
15-1/4" 387  
18"  
457  
20-3/4" 527  
23-1/2" 597  
26-1/4" 641  
31-3/4" 806  
37-1/4" 946  
42-3/4" 1086  
200  
225  
250  
300  
350  
400  
NOTE: If the furnace is equipped with a unit-mounted ductstat (Op-  
tion AG3), the sensing bulb must be removed from the mounting bracket  
(save the retainer clip) before the ductwork can be attached. See in-  
structions in Paragraph 22 for re-mounting the sensor.  
Figure 12B -  
Attachment  
of
F
Requirements and Suggestions for Connecting  
and Installing Ducts  
Type of Ductwork - The type of duct installation to be used de-  
pends in part on the type of construction of the roof (whether wood  
joist, steelbar joist, steel truss, pre-cast concrete) and the ceiling  
(whether hung, flush, etc.).  
Ductwork Material - Rectangular duct should be constructed of  
not lighter than No. 26 U.S. gauge galvanized iron or No. 24 B & S  
gauge aluminum.  
Ductwork Structure - All duct sections 24 inches or wider, and  
over 48 inches in length, should be cross broken on top and bottom  
and should have standing seams or angle-iron braces. Joints should  
be S and drive strip, or locked.  
Through Masonry Walls - No warm air duct should come in con-  
tact with masonry walls. Insulate around all air duct through ma-  
sonry walls with not less than 1/2" (1" is recommended) of insula-  
tion.  
Through Unheated Space - Insulate all exposed warm air ducts  
passing through an unheated space with at least 1/2" (1" is recom-  
mended) of insulation.  
Duct Supports - Suspend all ducts securely from adjacent build-  
ings members. Do not support ducts from unit duct connections.  
Duct Sizing - Proper sizing of the supply air ductwork is necessary  
to ensure a satisfactory heating installation. The recognized author-  
ity for such information is the Air Conditioning Contractors Asso-  
ciation, 1228 17th Street N.W., Washington, D.C. 20036. A manual  
covering duct sizing in detail may be purchased directly from them.  
Figure 12C -The  
seals between the  
furnace and the  
duct must be  
mechanical. "U"  
channel method is  
illustrated here.  
Removable Panels - The ducts should have removable access pan-  
els on both upstream and downstream sides of the furnace. These  
openings must be accessible when the furnace is in service and  
should be a minimum of 6" x 10" in size so smoke or reflected light  
may be observed inside the casing to indicate the presence of leaks  
in the heat exchanger. The covers for the openings must be attached  
in such a manner as to prevent leakage. See Figure 12A.  
Supply Air Duct/Furnace Horizontal Connection - The seal be-  
tween the furnace and the duct must be mechanical. Duct connec-  
tion should be made with "U" type flanges on the top and bottom of  
the connecting duct. Slide the duct over the flanges of the heater  
giving an airtight fit. Provide "U" type channels for the other side  
flanges to ensure tight joints. Use sheetmetal screws to fasten ducts  
and "U" channels to the furnace flange. See Figures 12B and 12C.  
CAUTION: Joints where ducts attach to furnace  
must be sealed securely to prevent air leakage  
into burner rack area. Leakage can cause poor  
combustion, pilot problems, shorten heat  
exchanger life and cause poor performance. See  
Hazard levels, page 2.  
Form 421, Page 12  
Download from Www.Somanuals.com. All Manuals Search And Download.  
12. Condensate Drain, Option CS1, for Furnaces Used with  
Refrigeration Systems  
Figure 13 - Condensate Drain, Option CS1 (P/N 31765)  
These furnaces are certified for installation upstream or downstream  
from refrigerated units supplying air below the dew point of the ambi-  
ent air surrounding the furnace. When installed downstream from a  
refrigeration system, condensation will form and therefore, adequate  
provision must be made to dispose of the condensate. A drain flange,  
Option CS1, may be installed on the furnace casing as shown in Figure  
13. When using Option CS1, seal all holes in the bottom pan. Termi-  
nate the drain outside of the building. NOTE: A 4-inch minimum clear-  
ance is required under the furnace if a 90o street elbow is used.  
Seal holes in bottom pan. Terminate drain outside of  
building. Periodic cleaning of the condensate collector and  
disposal system is required.  
Periodic cleaning of the condensate collection and the disposal system  
is required.  
13. Duct Furnace Air Flow Requirements  
The duct furnace must be installed on the positive pressure side of the field supplied blower. The air throughput must be within the CFM range  
stated on the heater rating plate. The air distribution must be even over the entire heat exchanger. Turning vanes should be employed in elbows or  
turns in the air inlet to ensure proper air distribution (See Paragraph 15). If it is determined that the blower CFM is greater than allowed or desirable,  
see Paragraph 14 for instructions on determining the correct size of bypass duct required. To determine temperature rise, the inlet and outlet air  
temperatures should be measured at points not affected by heat radiating from the heat exchanger. The following charts show the approved  
temperature rise range with the required CFM and the internal pressure drop for each size of unit.  
Model EEDU (80% thermal efficient)  
Size  
75  
100  
125  
140  
170  
200  
225  
250  
300  
350  
400  
Temperature  
Rise  
CFM P.D. CFM P.D. CFM P.D. CFM P.D. CFM P.D. CFM P.D. CFM P.D. CFM P.D. CFM P.D. CFM P.D. CFM P.D.  
1105 0.24 1475 0.43 1840 0.49 2065 0.65 2505 0.67 2945 0.67 3315 0.69 3685 0.67 4420 0.70 5160 0.75 5895 0.77  
920 0.16 1225 0.30 1535 0.33 1720 0.43 2085 0.46 2455 0.46 2765 0.47 3070 0.45 3685 0.47 4300 0.52 4915 0.52  
790 0.10 1050 0.21 1315 0.25 1475 0.32 1790 0.33 2105 0.35 2370 0.36 2630 0.34 3160 0.35 3685 0.38 4210 0.38  
695 0.07 920 0.16 1150 0.20 1290 0.24 1565 0.25 1840 0.26 2070 0.27 2300 0.26 2765 0.27 3225 0.28 3685 0.28  
615 0.05 815 0.12 1020 0.17 1145 0.20 1390 0.19 1635 0.20 1840 0.21 2045 0.20 2455 0.22 2565 0.23 3275 0.22  
50°F  
60°F  
70°F  
80°F  
90°F  
Model HEEDU (80% thermal efficient, high CFM)  
Size  
75  
100  
125  
140  
170  
200  
225  
250  
300  
350  
400  
Temperature  
Rise  
CFM P.D. CFM P.D. CFM P.D. CFM P.D. CFM P.D. CFM P.D. CFM P.D. CFM P.D. CFM P.D. CFM P.D. CFM P.D.  
2765 0.60 3685 1.09 4605 1.14 5160 1.50 6265 1.64 7370 1.64 8295 1.69 9215 1.67 11060 1.64 12900 1.64 14745 1.64  
1840 0.28 2455 0.50 3070 0.52 3440 0.66 4175 0.73 4915 0.73 5530 0.75 6140 0.72 7370 0.73 8600 0.73 9830 0.73  
1380 0.16 1840 0.28 2300 0.27 2580 0.36 3130 0.38 3685 0.39 4145 0.40 4605 0.40 5530 0.39 6450 0.40 7370 0.38  
1105 0.12 1475 0.18 1840 0.18 2065 0.22 2505 0.24 2945 0.24 3315 0.26 3685 0.24 4420 0.24 5160 0.25 5895 0.24  
920 0.10 1225 0.13 1535 0.14 1720 0.17 2085 0.17 2455 0.17 2765 0.18 3070 0.17 3685 0.17 4300 0.18 4915 0.17  
850 0.08 1130 0.11 1415 0.12 1585 0.15 1925 0.14 2265 0.14 2552 0.15 2835 0.14 3400 0.14 3970 0.15 4535 0.15  
20°F  
30°F  
40°F  
50°F  
60°F  
65°F  
--  
--  
--  
--  
--  
--  
--  
-- 1790 0.12 2105 0.12 2370 0.13 2630 0.11 3160 0.12 3685 0.13 4210 0.13  
70°F  
14. Constructing Bypass Duct  
Bypass CFM  
Pressure Drop through the Furnace  
Width 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50  
When the CFM of air throughput is greater than desirable or permis-  
sible for the unit, a bypass duct may be constructed. Follow these in-  
structions to determine the correct size of the bypass duct.  
"A"  
3"  
4"  
5"  
6"  
7"  
8"  
9"  
10"  
490 530 610 700 780 830 900 960 1010  
630 750 870 980 1090 1160 1250 1310 1400  
850 1010 1190 1300 1410 1520 1640 1730 1810  
1050 1290 1480 1650 1800 1940 2090 2200 2320  
1250 1510 1760 1960 2180 2320 2500 2650 2800  
1490 1810 2100 2350 2560 2760 2940 3110 3290  
1700 2100 2400 2700 2970 3200 3400 3600 3800  
1920 2350 2760 3090 3650 4020 4300 4550 4800  
2) Subtract the allowable CFM from the actual CFM of the installa-  
tion to determine how much air must be diverted through the by-  
pass duct.  
Example:  
Blower CFM 3000  
Allowable CFM -1790  
Bypass CFM 1210  
Figure 13 - Bypass Duct  
Directions for Sizing Bypass Duct  
1) From the tables in Paragraph 13, find the pressure drop (P.D.) and  
3) Go to the column in the Bypass CFM Chart that is closest to the  
pressure drop through the heater. Move down in that column until  
you find the CFM closest to the answer in Step 2).  
the allowable CFM for the furnace that is being installed.  
Example:  
Standard Size 170 @ 70oF temperature rise;  
P.D. .33; CFM 1790  
Example:  
P.D. .35  
Bypass CFM 1520  
RGM Form 421, Mfg No. 150492, Page 13  
Download from Www.Somanuals.com. All Manuals Search And Download.  
15. Furnace Blower Connections  
14. Bypass Duct (cont'd)  
Requirements: Proper arrangements of blower and duct furnace with respect to  
angle of approach of the duct connection and the arrangement of the discharge  
opening of the blower are shown. Blowers should be bottom horizontal dis-  
charge when coupled to the duct furnace. When a top horizontal discharge blower  
is connected to the duct furnace, be sure that sufficient length of duct is pro-  
vided to permit even flow of air at the end of the duct. Or, baffles may be in-  
serted between the blower and the heater to assure an even flow of air across the  
heat exchanger. See illustrations in Figure 14.  
4) Move to the left column to find out the required size of  
the bypass duct.  
Example:  
Bypass Duct  
Size is 5"  
Depth of the bypass duct is 18" on both inlet and outlet ends.  
Bypass duct must be located on side opposite controls and 2"  
from the heat exchanger side panel.  
NOTE: Not all capacities are covered in this chart. If your  
installation is not covered, the correct size may be determined  
by consulting the factory representative.  
WARNING: The furnace must be installed on the  
positive pressure side of the air-circulating blower. See  
Hazard Levels, page 2.  
Figure 14  
Form 421, Page 14  
Download from Www.Somanuals.com. All Manuals Search And Download.  
16. Combustion Air Proving  
Switch  
Figure - 15 - Field Wiring Connections  
Connect Field  
Wiring in the  
Electrical Box  
The combustion air proving switch is a pressure sensitive switch  
that monitors air pressure to ensure that proper combustion air flow  
is available. The switch is a single pole - normally open - device  
which closes when a decreasing pressure is sensed in the outlet duct  
of the flue gas collection box.  
On start-up when the heater is cold, the sensing pressure is at the  
most negative level, and as the heater and flue system warm up, the  
sensing pressure becomes less negative. After the system has reached  
equilibrium (about 20 minutes), the sensing pressure levels off.  
If a restriction or excessive flue length or turns cause the sensing  
pressure to become less than the switch setpoint, the pressure switch  
will function to shut off the main burners. The main burners will  
remain off until the system has cooled and/or the flue system resis-  
tance is reduced. The Table on the below lists the approximate water  
column negative pressure readings and switch setpoints for sea level  
operating conditions.  
Line Voltage  
Connection Tabs  
Operating Sequence  
1. Set thermostat at lowest setting  
2. Turn on the power to the unit.  
3. Turn on main and pilot manual gas valve.  
4. Set thermostat at desired setting.  
Start-Up Cold Equilibrium Set Point "Off" Set Point "On"  
5. Thermostat calls for heat energizing the venter motor.  
6. Pressure switch closes, energizing the pilot gas valve and spark gap to  
produce a pilot flame on each operating cycle. The sensing probe proves  
the presence of pilot flame and energizes the safety switch portion of  
the control. The switch action de-energizes the spark gap and ener-  
gizes the main gas valve.  
-1.0" w.c.  
-0.60" w.c.  
-0.48" w.c.  
-0.65" w.c.  
DANGER: Safe operation of this unit requires  
proper venting flow. NEVER bypass  
combustion air proving switch or attempt to  
operate the unit without the venter running and  
the proper flow in the vent system. Hazardous  
conditions could result. See Hazard Levels,  
page 2.  
7. Fan control (Optional) senses heat exchanger temperature energizing  
the fan or blower motor of the air handler.  
8. If the pilot flame is extinguished during main burner operation, the  
sensing probe detects the absence of the flame and causes the safety  
switch to close the main valve. On units with standard intermittent  
spark pilot systems, the spark gap recycles. On units with optional  
spark ignition with lockout, if the pilot is not established within the  
timing cycle (approximately 120 seconds), the unit locks out and must  
be reset by interrupting power to the control circuit.  
17. Electrical Supply and  
Connections  
Disconnect Switch  
A disconnect switch is a required part of this installation. Switches are  
available, as options or parts, or may be purchased locally. When ordered  
as an optional component, the disconnect switch is shipped separately.  
All electrical wiring and connections, including electrical ground-  
ing MUST be made in accordance with the National Electric Code  
ANSI/NFPA No. 70 (latest edition) or, in Canada, the Canadian Elec-  
trical Code, Part I-C.S.A. Standard C22.1. In addition, the installer  
should be aware of any local ordinances or gas company require-  
ments that might apply.  
The disconnect switch may be fusible or non-fusible. When installing, be  
careful that the conduit and switch housing are clear of furnace panels  
and inspection plates. Allow at least four feet of service room between  
the switch and removable panels.  
Check the rating plate on the heater for the supply voltage and cur-  
rent requirements. A separate line voltage supply with fused discon-  
nect switch should be run directly from the main electrical panel to  
the furnace, making connection to leads in the junction box. All  
external wiring must be within approved conduit and have a mini-  
mum temperature rise of 63oF. Conduit from the disconnect switch  
must be run so as not to interfere with the service panels of the  
furnace.  
Control Thermostat  
A thermostat is not standard equipment but is an installation requirement.  
Use either an optional thermostat available with the heater or a field-  
supplied thermostat. Install according to the thermostat manufacturer's  
instructions.  
A 24 volt thermostat must be used to actuate low voltage gas controls. If  
line voltage from the thermostat to the unit is desired, consult the factory  
representative.  
If the heater has field-installed options that require electrical con-  
nections, consult the instruction sheet and wiring diagram supplied  
in the option package.  
Wiring between the thermostat and the heater must be suitable for a tem-  
perature rise of 63oF. Labeled thermostat leads are provided in the heater  
junction box for connection of thermostat wiring.  
CAUTION: If any of the original wire as  
supplied with the appliance must be replaced,  
it must be replaced with wiring material having  
a temperature rating of at least 105oC, except  
for sensor lead wires which must be 150oC. See  
Hazard Levels, page 2.  
Thermostats should be located five feet above the floor on an inside wall,  
not in the path of warm or cold air currents, not in corners where air may  
be pocketed. Do NOT install on cold air walls. For specific connection  
details, refer to instruction packet with the thermostat.  
If more than one unit is cycled from one thermostat, separately activated  
relays must be substituted at unit thermostat connections.  
Specific wiring diagrams that include standard and factory-installed  
options are included with the heater. Typical wiring diagrams are  
on page 17.  
RGM Form 421, Mfg No. 150492, Page 15  
Download from Www.Somanuals.com. All Manuals Search And Download.  
Typical Wiring Diagrams -- Refer to the diagram supplied with the heater for specific  
controls or optional equipment.  
Single-Stage with Intermittent Spark Pilot System with or without Lockout  
W.D. 110920  
Field and Replacement Wiring Notes  
1. Dotted wiring supplied by others.  
2. Thermostat supplied as optional equipment.  
3. Use #14 gauge wire for line wiring to unit.  
4. Use #18 gauge wire for control wiring.  
5. Line and blower motor branch circuit wire sizes should be of a size to  
prevent voltage drops beyond 5% of supply line voltage.  
6. On 208-230V units, the control transformer has dual voltage primary.  
For 208 volt units, use black and red leads (cap yellow).  
For 230 volt units, use black and yellow leads (cap red).  
On 115 volt units, the control transformer is single voltage primary. Use  
black and yellow leads for 115 volt.  
Secondary side of transformer (24V), use blue and brown leads.  
7. Sizes 75-250, 208 volts, the venter motor wires are black and white (cap  
red).  
Sizes 75-250, 230 volts, the venter motor wires are red and white (cap  
black).  
Sizes 75-250, 115 volts, the venter motor wires are black and white.  
Sizes 300-400, all voltages, the venter motor wires are black and white.  
CAUTION: If any of the original wire as supplied  
Field Control Wiring - Length and Gauge  
with the appliance must be replaced, it must be  
Minimum  
Recommended Wire  
Gauge  
Total Wire  
Length  
Distance from Unit  
to Control  
replaced with wiring material having a  
temperature rating of at least 105oC, except for  
sensor lead wires which must be 150oC. See  
Hazard Levels, page 2.  
150'  
250'  
350'  
75'  
125'  
175'  
#18 gauge  
#16 gauge  
#14 gauge  
Form 421, Page 16  
Download from Www.Somanuals.com. All Manuals Search And Download.  
Two-Stage with Intermittent Spark Pilot System with or without Lockout  
W.D. 110824  
6
L1  
(HOT)  
L2  
(COM)  
7
LINE/1/60  
OPERATING SEQUENCE  
1. SET THERMOSTAT SWITCH AT "OFF" POSITION.  
VENTER MOTOR  
(SEE NOTE #7  
FOR WIRING)  
8
2. TURN ON MAIN AND PILOT MANUAL GAS VALVES.  
VENTER RELAY  
CONTACTS  
3. TURN ON POWER TO UNIT.  
4. SET THERMOSTAT SWITCH AT "ON" POSITION.  
5. LOW STAGE OF THERMOSTAT CALLS FOR HEAT ENERGIZING THE VENTER MOTOR.  
6. PRESSURE SWITCH CLOSED ENERGIZING THE PILOT GAS VALVE AND SPARK GAP  
TO PRODUCE A PILOT FLAME ON EACH OPERATING CYCLE. THE SENSING PROBE  
PROVES THE PRESENCE OF THE PILOT FLAME AND ENERGIZES THE SAFETY  
SWITCH PORTION OF THE CONTROL. THE SWITCH ACTION DE-ENERGIZES THE  
SPARK GAP AND ENERGIZES THE LOW STAGE GAS VALVE.  
BK  
2
BK  
4
BK OR R  
W
9
BK OR R  
LIMIT CONTROL  
BK BK  
R
LINE VOLT  
BK  
Y
10  
11  
12  
13  
14  
15  
16  
17  
18  
19  
20  
21  
22  
40 VA. CONTROL  
TRANSFORMER  
7. HIGH STAGE OF THERMOSTAT CALLS FOR HEAT ENERGIZING THE HIGH STAGE  
GAS VALVE, FIRING UNIT AT FULL RATE.  
BL  
BL  
BR  
8. IF THE FLAME IS EXTINGUISHED DURING MAIN BURNER OPERATION THE  
SAFETY SWITCH CLOSES THE MAIN VALVE AND RECYCLES THE SPARK GAP.  
ON UNIT EQUIPPED WITH G77ONGC-4 LOCKOUT CONTROL, IF PILOT IS  
NOT ESTABLISHED WITHIN 120 SECONDS (APPROX.) UNIT LOCKS OUT  
AND MUST BE REST BY INTERRUPTING POWER TO CONTROL CIRCUIT.  
(SEE LIGHTING INSTRUCTIONS)  
24V  
O
O
12  
BR  
VENTER  
RELAY COIL  
9
CR  
3
1
NOTES  
1. DOTTED WIRING SUPPLIED AND INSTALLED BY OTHERS.  
BR  
BR  
2. CAUTION: IF ANY OF THE ORIGINAL WIRE AS SUPPLIED WITH THE APPLIANCE  
MUST BE REPLACED, IT MUST BE REPLACED WITH WIRING MATERIAL HAVING  
A TEMPERATURE RATING OF A LEAST 105 DEGREES C., EXCEPT FOR ENERGY  
CUT-OFF OR SENSOR LEAD WIRE WHICH MUST BE 150 DEGREES C.  
3. LIMIT WIRE TO BE #18 GA. 200 C. SF-1 OF SEW-1.  
4. USE #14 GA. WIRE FOR LINE WIRING TO UNIT.  
5. LINE AND BLOWER MOTOR BRANCH CIRCUIT WIRE SIZES SHOULD BE OF A SIZE  
TO PREVENT VOLTAGE DROP BEYOND FIVE PERCENT OF SUPPLY LINE VOLTAGE.  
6. ON 208/230V. UNITS THE CONTROL TRANSFORMER HAS A DUAL VOLTAGE PRIMARY.  
FOR 208V. UNITS USE BLACK AND RED LEADS (CAP YELLOW).  
GRND.  
STRIP  
W
FOR 230V. UNITS USE BLACK AND YELLOW LEADS (CAP RED).  
ON 115V. UNITS THE CONTROL TRANSFORMER IS SINGLE VOLTAGE PRIMARY.  
USE BLACK AND YELLOW LEADS FOR 115V.  
SECONDARY SIDE OF TRANSFORMER (24V.) USE BLUE AND BROWN LEADS.  
O7.N 75-250 208V UNITS, THE VENTER MOTOR WIRES ARE BLACK AND WHITE (CAP RED)  
ON 75-250 230V UNITS, THE VENTER MOTOR WIRES ARE RED AND WHITE (CAP BLACK)  
ON 75-250 115V UNITS AND 300-400 UNITS ALL VOLTAGES, THE VENTER MOTOR WIRES  
ARE BLACK AND WHITE.  
G67BG-5  
W.R. TWO STAGE  
REDUNDANT  
GAS VALVE  
RECYCLE  
OR  
G770NGC-4  
LOCKOUT  
BK  
3
1
IGNITION  
CONTROLLER  
FLAME SENSING  
PROBE  
FIELD CONTROL WIRING  
TOTAL WIRE MINIMUM RECOMMENDED  
BR  
R
4
2
LENGTH  
150 FEET  
250 FEET  
350 FEET  
WIRE SIZE  
#18 GA.  
#16 GA.  
#14 GA.  
O
PRESSURE  
SWITCH  
BK  
IGNITOR  
GRND  
O
BK  
W1  
2
BL  
1
4
3
CHASSIS GRND.  
R
R
W2  
18. Limit Switch  
Figure 16 - Access  
to the limit switch  
depends on the  
installation  
A non-adjustable high limit switch mounted at the outlet air side of the  
heat exchanger acts to shut off the gas supply in the event of air handler  
motor failure, lack of correct air flow (See Paragraph 13), or restriction  
due to filters and/or duct design. See Figure 16 for mounting and ser-  
vice.  
Depending on accessibility, the limit switch may be serviced from ei-  
ther the outside of the unit or from the inside through the access panel  
in the discharge duct. When units are installed side by side, the service  
access panel must be in either the top or bottom of the ductwork for  
limit switch service. (See Paragraphs 8 and 11.)  
View of limit  
switch from  
"inside" the  
furnace  
WARNING: If you turn off the power supply,  
turn off the gas. See Hazard Levels, page 2.  
Access to  
limit switch  
from  
"outside"  
the furnace  
RGM Form 421, Mfg No. 150492, Page 17  
Download from Www.Somanuals.com. All Manuals Search And Download.  
19. Fan Control (Optional,  
Field Installed)  
NOTE: Required with makeup air gas control options; see  
Paragraphs 22 and 23.  
Figure 17 - Installation of Optional Fan Control  
Kit, Option CQ1 (P/N 57960)  
1. Fan control provides the following: a) Delay of fan op-  
eration preventing circulation of cold air, and b) Fan op-  
eration as long as the unit is hot.  
2. The fan control provides additional safety by keeping the  
fan in operation in the event that the gas valve fails to  
close when the thermostat is satisfied.  
3. To be sure that the fan can continue to operate, the power  
supply to the heater MUST NOT be interrupted except  
when servicing the heater.  
4. If the customer wants the heater off at night, the gas valve  
circuit SHOULD BE OPENED by a single pole switch  
wired in series with the thermostat. Some thermostats are  
provided with this feature. Multiple units controlled from  
a single thermostat are shut off in the same manner. For  
proper operation, be sure fan control wiring is observed.  
See Figure 17 for installation of fan control and wiring.  
WARNING: If you turn off the power  
supply, turn off the gas. See Hazard  
Levels, page 2.  
Location of the Fan  
Control Mounting Holes  
Typical Fan Control  
Wiring (W.D. 145977)  
Install the gasket supplied in  
the option kit between the  
fan control and the duct.  
Drill 13/16" diameter hole for element  
Drill four 1/8" diameter holes for screws  
4"  
(102mm)  
Fan Control P/N 147611,  
Honeywell Model  
L4064A1347  
3"  
(76mm)  
3/4"  
(19mm)  
3"  
(76mm)  
Heater  
2-3/8"  
(60mm)  
Discharge Duct  
Recommended dial setting for most  
conditions 130oF ON and 100oF OFF  
DP-ST Control Switch (Used with Options  
AG3, AG8, AG9, AG15, and AG16)  
Form 421, Page 18  
Download from Www.Somanuals.com. All Manuals Search And Download.  
20. Gas Valve  
Figure 18 - Ductstat/Sensing Bulb Locations for  
Furnace with Option AG3  
All furnaces are equipped with a 24-volt combination valve which  
includes the automatic electric on-off valve controlled by the room  
thermostat, the pressure regulator, the safety pilot valve, and the  
manual shutoff valve. The standard gas valve allows for single-stage  
control from a single-stage, 24-volt thermostat.  
The ductstat provided with Op-  
tion AG3 is attached to the side  
of the furnace at the factory.  
The sensor is mounted on a  
bracket on the inner part of  
the furnace duct side.  
WARNING: The operating valve is the prime  
safety shutoff. All gas supply lines must be free  
of dirt or scale before connecting the unit to  
ensure positive closure. See Hazard Levels, page  
2.  
Side  
View  
Ductstat  
Front  
View  
Bulb  
Retaining  
Clip  
Ductstat  
Bracket  
21. Optional Two-Stage Operation -  
Heating Only Application  
Sensing  
Bulb  
NOTE: This option is not available on Size 75 using propane gas.  
The standard combination control valve is replaced with a two-stage  
combination gas control valve providing for low fire or high fire  
operation controlled by a two-stage thermostat. First stage (low fire)  
is factory set (not field adjustable). Both high and low stages are  
controlled by a Servo regulator, maintaining constant gas input un-  
der wide variations in gas supply pressure. See instructions packed  
with the unit for specific gas valve specifications, wiring, and oper-  
ating instructions.  
Du
Sensing Bulb  
Bracket  
The Sensor and the ductstat are connected by a permanently attached  
capillary tubing. In order to attach the discharge ductwork, the sensor  
must be removed form the bracket (save the retaining clip) and the  
capillary tubing moved out of the way. After the ductwork is attached  
to the furnace (See Paragraph 12), a hole must be made in the duct-  
work to allow for the sensor to be re-installed on the bracket (capil-  
lary tubing with sensor will run through the hole). A removable ac-  
cess panel must be provided in the ductwork as shown in Figure 12A,  
Paragraph 12.  
22. Optional Two-Stage Operation -  
Makeup Air Application  
NOTES: Requires field installed fan control, see Paragraph 19. This  
option is not available on Size 75 using propane gas.  
Two-stage makeup air units are equipped with a two-stage gas valve,  
but instead of control from a two-stage room thermostat, the outlet  
air temperature is monitored and controlled by a two-stage ductstat.  
When the discharge air temperature drops to the setpoint, low fire is  
energized. If low fire cannot satisfy the ductstat setting, high fire is  
energized.  
Parts Required and Instructions:  
Since the sensor is larger than  
Qty P/N  
Description  
the tubing, a gasket and gasket  
retainer plate are needed to plug  
the hole and protect the capillary  
tubing where it passes through  
1
1
7726 Gasket  
7727 Gasket Retainer Plate  
Makeup air applications are usually adjusted to discharge an outlet  
air temperature between 65oF and 75oF. In all applications, the al-  
lowable temperature rise of the furnace in the installation dictates the  
limits of the ductstat temperature setting.  
the ductwork. These parts were shipped loose with the furnace. Two  
field-supplied sheet metal screws will be needed to attach the plate.  
1) Drill the Holes - Refer to the illustration below and select a loca-  
tion on the ductwork so that a minimum length of capillary tubing  
will be inside the ductwork. Following the pattern, drill holes in  
the ductwork.  
Depending on the option selection, the factory-installed sensor is  
either field-connected by capillary tubing to the unit-mounted ductstat  
(Option AG3), Figures 18 and 19, or electrically connected to a re-  
mote electronic remote temperature selector (Options AG15 or AG16,  
Figure 20). The remote temperature selector is available with or with-  
out a display module.  
Optional Ductstat with Capillary Tubing (Option AG3) -- The  
ductstat is attached to the side of furnace and is connected by capil-  
lary tubing to the sensor which is mounted on a bracket on the inner  
part of the furnace duct side (See Figure 18). In order to attach the  
discharge ductwork to the furnace, the sensor must be removed from  
the bracket and the capillary tubing moved out of the way. Follow  
the illustrated instructions in Figure 18 for re-connecting the ductstat  
after the ductwork is attached.  
2) Re-Mount the Sensor on the Bracket - Push the sensor through  
the hole. Remove the ductwork access plate. Reaching through  
the access hole, use the retaining clip to re-mount the sensor on  
the bracket.  
3) Install the Gasket - Slide the gasket and hole retainer plate over  
the capillary tubing. With the gasket next to the ductwork, attach  
the hole retaining plate with field-supplied sheet metal screws (as  
illustrated above). Close the ductwork access panel.  
The ductstat dial is illustrated in Figure 19. The dial has an adjust-  
able range from 60oF to 100oF with a fixed differential of 2-1/2oF.  
Due to different CFM settings and outside air temperatures, the aver-  
age downstream outlet air temperature may not match the ductstat  
exactly. After the installation is complete, adjust the ductstat setpoint  
to achieve the desired average outlet air temperature.  
RGM Form 421, Mfg No. 150492, Page 19  
Download from Www.Somanuals.com. All Manuals Search And Download.  
els. Electronic modulation control systems for makeup air applications  
controlled by a duct sensor and temperature selector (55-90oF) are iden-  
tified as either Option AG8 or Option AG9. The temperature selector  
setting for Option AG8 is on the amplifier; Option AG9 has a remote  
temperature selector. Both systems are available with an override ther-  
mostat. Options AG8 and AG9 for makeup air applications apply to  
duct furnace and packaged systems.  
22. Optional 2-Stage Operation (cont'd)  
Dial has no temperature markings. Pin on adjustment  
screw pointing to "B" equals approximately 70oF.  
Computer Controlled Electronic Modulation between 50% and  
100% Firing Rate (Option AG21) - With this  
option the furnace is equipped with a Maxitrol A200  
Figure 19 -  
Ductstat  
Control in  
Option AG3  
(Mounted in  
inverted  
signal conditioner which operates much the same  
way as the amplifier above to control the regulator  
valve. The conditioner accepts an input signal of  
either 4-20 milliamps or 0-10 volts from a customer-  
supplied control device such as a computer. With the dip switches on  
the conditioner in the "on" positions, the conditioner accepts a 4-20  
milliamp signal. In the "off" positions, the conditioner accepts a 0-10V  
signal. The conditioner converts the signal to the 0 to 20 volt DC cur-  
rent required to control the modulating valve.  
position)  
Optional Ductstat with Electronic Remote Setpoint Module (Op-  
tions AG15 and AG16) -- The field-installed sensing probe is field-  
wired to a remote temperature selector with a temperature operating  
range to 130oF. The remote modules and a required transformer are  
shipped separately for field installation. (Do not wire the remote mod-  
ule to the control transformer on the furnace.) Follow the wiring dia-  
gram with the unit and the manufacturer's instructions for wiring and  
installation. There will be one module for selecting temperature and  
one-stage adder module. Option AG16 includes the digital display  
module. See Figure 20.  
24. Pilot and Ignition Systems  
A gas-fired intermittent pilot is standard. The vertical pilot is located  
under the aeration panel on the control end of the burner tray and is  
accessible only after the burner rack has been removed. Remove the  
pilot for maintenance or service, such as checking the wiring and clean-  
ing. (See Paragraph 30.) All pilots are target type with lint-free feature.  
Pilot gas pressure should be the same as supply line pressure. (See  
Paragraph 9.) If required, adjust the pilot flame length to approximately  
1-1/4" with the pilot adjustment screw in the control valve body.  
CAUTION: The remote temperature selector  
heat/cool selector switch is factory-set in cool  
position. To function properly, set switch to heat  
position.  
NOTE: This model furnace manufactured prior to 11/95 had a hori-  
zontal pilot with a spark gap of 7/64".  
Intermittent Spark Ignition Safety Pilot Systems -- There are two  
types of intermittent spark pilots -- one type shuts off the pilot gas flow  
between the cycles and the other not only shuts off the pilot gas flow  
between cycles but also has a lockout device that stops the gas flow to  
the pilot if the pilot fails to light in 120 seconds. This lockout feature  
requires manual reset by interruption of the thermostat circuit. Pro-  
pane units require the spark ignition system with the lockout device.  
Figure 20 - Remote  
Temperature  
Selector, Stage-  
Adder Module, and  
Optional Display  
Module for Ductstat  
in Two-Stage  
Ignition Controller -- As part of the intermittent safety pilot systems,  
the ignition controller provides the high voltage spark to ignite the  
pilot gas and also acts as the flame safety device. After ignition of the  
pilot gas, the ignition controller electronically senses the pilot flame. A  
low voltage DC electrical signal is imposed on the separate metal probe  
in the pilot assembly. The metal probe is electrically insulated from  
ground. The pilot flame acts as a conduction path to ground complet-  
ing the DC circuit and proving pilot flame. With pilot flame proven,  
the ignition controller energizes the main gas valve.  
Makeup Air Control  
Options (Option  
AG15 or AG16)  
23. Optional Electronic Modulation  
Note: Requires field-installed fan control.  
The type and capability of the electronic modulation system, depends  
on the option selected. Electronic modulation options are identified by  
a suffix to the Serial No. printed on the heater rating plate. AG7 is  
identified as MV-1; AG8 is identified as MV-3; AG9 is identified as  
MV-4; and AG21 is identified as MV-A.  
If no spark occurs, check the following:  
a) Voltage between blue and white terminals (non-lockout type pilot)  
and Terminals 2 and 5 (lockout type pilot) on the ignition controller  
should be at least 20 volts and no higher than 32 volts. Refer to  
Troubleshooting (Paragraph 32) if no voltage is observed.  
b) Short to ground in the high tension lead and/or ceramic insulator.  
c) Pilot spark gap should be approximately .100". (NOTE: This model  
furnace manufactured prior to 11/95 had a horizontal pilot with a  
spark gap of 7/64".)  
Electronic Modulation between 50% and 100% Firing Rate (Op-  
tions AG7, AG8, AG9) - Depending on the heat requirements as es-  
tablished by the thermistor sensor, the burner modulates between 100%  
and 50% firing. The thermistor is a resistor that is temperature sensi-  
tive in that as the surrounding temperature changes, the Ohms resis-  
tance changes through the thermistor. This change is monitored by the  
solid state control center (amplifier) which furnishes varying DC cur-  
rent to the modulating valve to adjust the gas input.  
NOTE: When checking for spark with the pilot burner assembly re-  
moved from the burner rack, the pilot assembly must be grounded to  
the heater for proper spark.  
Each modulating valve is basically a regulator with electrical means of  
raising and lowering the discharge pressure. When no DC current is  
fed to this device, it functions as a gas pressure regulator, supplying  
3.5" w.c. pressure to the main operating valve.  
If the above conditions are normal and no spark occurs, replace the  
ignition controller.  
If the main gas valve fails to open with a normal full size pilot flame  
established, check for the following:  
a) Voltage between black and brown leads on the main gas valve is 20  
to 32 VAC and there is no main gas flow with the built-in manual  
valve in FULL OPEN position -- the main valve is defective.  
Refer to the wiring diagram supplied with the furnace for proper wir-  
ing connections. Electronic modulation for heating controlled by a spe-  
cially designed room thermostat (60o-85oF) is identified as Option AG7  
and is available on unit heater, duct furnace and packaged heater mod-  
Form 421, Page 20  
Download from Www.Somanuals.com. All Manuals Search And Download.  
b) No voltage between black and brown leads on the main  
gas valve -- check for disconnected or shorted flame sen-  
sor lead or flame sensor probe.  
26. Burner Air Adjustment  
Burner air shutters are not normally required on natural gas furnaces. Air shut-  
ters are supplied on propane gas units and may require adjustment.  
When the above conditions are normal and the main gas flow  
is still off, the ignition controller is probably defective.  
Before making any adjustments to the air shutters, allow the heater to operate for  
about fifteen minutes with the air shutters open. The slotted screw on the end  
manifold bracket moves the air shutters and adjusts all burners simultaneously.  
Turning the screw clockwise opens the shutters; counterclockwise closes the  
shutters. After the furnace has been in operation for 15 minutes, close the air  
shutters observing the flame for yellow-tipping. Open the shutters until the yel-  
low disappears. A limited amount of yellow-tipping is permissible for propane  
gas. Other fuels should not display any yellow-tipping.  
25. Burners and Carryover  
System  
These duct furnaces have individually formed steel burners  
with accurately die-formed ports to give controlled flame  
stability without lifting or flashback with either natural or  
propane gas. The burners are lightweight and factory mounted  
in an assembly which permits them to be removed as a unit  
for inspection or service.  
When making the adjustment, close the air shutters no more than is necessary to  
eliminate the problem condition.  
DANGER: Failure to install and/or adjust air shutters  
according to directions could cause property damage,  
personal injury, and or death.  
All burners are equipped with two flash carryover systems  
that receive a supply of gas simultaneously with the main  
burner. During regular service, check the main burner ports,  
the carryover assemblies, and the orifices for cleanliness.  
27. Check Installation and Start-Up  
Check the installation prior to start-up:  
Start-Up  
oCheck suspension. Unit must be secure and level.  
oTurn electric and gas supply on to the furnace. Adjust the thermo-  
stat or ductstat so that a call for heat exists. Observe for complete  
sequencing of safety pilot and ignition.  
oBe certain the electrical supply matches voltage rating of the fur-  
nace. (Refer to the rating plate.)  
Check installation after start-up:  
oWith the unit in operation, measure manifold gas pressure. Mani-  
fold pressure for natural gas should be 3.5" w.c. and 10" w.c. for  
propane gas. See Paragraph 9.  
oCheck all field wiring against the wiring diagram. Be sure wire  
gauges are as required for the electrical load. Verify that fuses or  
circuit breakers are in place and sized correctly.  
oCheck clearances from combustibles. Requirements are shown in  
oTurn the unit off and on, pausing two minutes between each cycle.  
Paragraph 5.  
Observe for smooth ignition. On two-stage or modulating burner  
systems, manipulate temperature adjustment slowly up and down to  
see if control is sequencing or modulating properly. Raising tem-  
perature setting drives burner on or to full fire.  
oIf installed in a confined space, verify that the furnace has adequate  
combustion air supply. See Paragraph 5.  
oCheck vent system to be sure that it is installed according to the  
instructions in Paragraph 10. Be sure to have used an approved  
vent terminal.  
oObserve burner flame at full fire. Natural gas flame should be about  
1-1/2" in height with blue coloring. Propane gas flame should be  
approximately the same length with blue coloring. Yellow tipping  
may appear on propane gas. If yellow extends beyond 1/2 to 3/4",  
adjust air shutters. See Paragraph 26 .  
oCheck piping for leaks and proper gas line pressure. Bleed gas  
lines of trapped air. See Paragraph 9.  
a) Turn manual shutoff valve to off position.  
b) Turn gas supply on.  
oChecked the limit control. With the heater on, completely block off  
distribution air. The limit control should open within a few minutes,  
shutting off the gas supply to the main burners.  
c) Observe gas meter for movement, or  
d) Attach pressure gauge readable to .1" w.c. and after turning gas on  
for ten seconds, turn gas supply off. No change in pressure should  
occur over a three-minute period.  
oPlace "Owner's Envelope" containing Limited Warranty Card, this  
e) If either c) or d) above indicate a leak, locate leak by brushing a  
leak-detecting solution on all fittings. Bubbles will appear at a leak.  
Repair and repeat tests.  
booklet, and any optional information in an accessible location near  
the heater. Follow the instructions on the envelope.  
DANGER: The gas burner in this gas-fired equipment is designed and equipped to provide safe and  
economically controlled complete combustion. However, if the installation does not permit the burner  
to receive the proper supply of combustion air, complete combustion may not occur. The result is  
incomplete combustion which produces carbon monoxide, a poisonous gas that can cause death. Safe  
operation of indirect-fired gas burning equipment requires a properly operating vent system which  
vents all flue products to the outside atmosphere. FAILURE TO PROVIDE PROPER VENTING  
WILL RESULT IN A HEALTH HAZARD WHICH COULD CAUSE SERIOUS PERSONAL INJURY  
OR DEATH.  
Always comply with the combustion air requirements in the installation codes and in Paragraph 5.  
Combustion air at the burner should be regulated only by manufacturer-provided equipment. NEVER  
RESTRICT OR OTHERWISE ALTER THE SUPPLY OF COMBUSTION AIR TO ANY HEATER.  
Indoor units installed in a confined space must be supplied with air for combustion as required by  
Code and in Paragraph 5 of this heater installation manual. MAINTAIN THE VENT SYSTEM IN  
STRUCTURALLY SOUND AND PROPERLY OPERATING CONDITION.  
RGM Form 421, Mfg No. 150492, Page 21  
Download from Www.Somanuals.com. All Manuals Search And Download.  
SERVICE AND MAINTENANCE  
WARNING: If you turn off the power supply,  
turn off the gas. See Hazard Levels, page 2.  
CAUTION: When cleaning, wearing eye  
protection is recommended.  
Maintenance Requirements -- Like all quality equipment, this unit  
will operate with a minimum of maintenance. However, to ensure long  
life and satisfactory performance, the following service schedule is rec-  
ommended. When servicing, follow standard safety procedures and  
those specific instructions and warnings in this manual.  
Figure 22 --  
Vertical Spark  
Pilot  
Furnaces should be inspected at the beginning of each heating season  
and then once every four (4) months where the equipment is working  
under normal conditions. If the furnace is located where an unusual  
amount of dust or soot or other impurities are contained in the air,  
more frequent inspection is recommended. Clean the heat exchanger  
(inside and outside) annually.  
When re-installing  
the pilot, be sure to  
include the pilot  
hole cover plate.  
Figure 23 - Pilot Location  
Burner  
28. Burner Rack Removal Instructions  
1. Turn off the gas supply.  
Rear  
2. Turn off the electric supply.  
Support  
3. Remove bottom rear panel (located on the manifold side of the fur-  
nace) by removing the two screws from each side.  
4. Mark and disconnect electric valve leads.  
6. Uncouple the union in the gas supply.  
7. Remove two sheet metal screws in the bottom of the burner rack  
assembly.  
of burner  
3/4"  
(+ or - 1/32")  
of pilot and  
sensor  
8. Pull "drawer-type" burner rack out of the furnace.  
To disassemble the burner rack:  
1. Remove flash carryover system (screws located at rear of burner  
drawer).  
2. Remove burner hold down clamp (located inside burner drawer un-  
derneath the pilot).  
3. Pull main burners horizontally away from injection opening and  
lift out.  
disassemble the ignition controller. There are no field replaceable com-  
ponents in the control enclosure.  
Follow the instructions in Paragraph 29 to clean. To re-assemble and  
replace, reverse the above procedures being careful not to create any  
unsafe conditions.  
CAUTION: Due to high voltage on pilot spark  
wire and pilot electrode, do not touch when  
energized. See Hazard Levels, page 2.  
Burners - Normally it is unnecessary to clean the main burners but  
during the annual cleaning of the heat exchanger tubes it is wise to  
inspect the burners for plugged ports. Main burners may be cleaned  
using air pressure. Use an air nozzle to blow out scale and dust accu-  
mulation from the burner ports. Alternately blow through the burner  
ports and the venturi. Use a fine wire to dislodge any stubborn par-  
ticles. Do not use anything that might change the port size.  
29. Cleaning Pilot and Main Burners  
Pilot - The pilot is located under the aeration panel on the control end  
of the burner tray and is accessible only after the burner rack assembly  
has been removed. In the event the pilot flame is short and/or yellow,  
check the pilot orifice for blockage caused by lint or dust accumula-  
tion. Remove the pilot orifice and clean with air pressure. DO NOT  
REAM THE ORIFICE. Check and clean the aeration slot in the pilot  
burner.  
Clean the metal sensing probe and the pilot hood with an emery cloth  
and wipe off the ceramic insulator. Check the spark gap; spark gap  
should be maintained  
Clean the burner rack flash carryover systems with air pressure.  
Burner Orifices for Sea Level Operation  
to .100". After the  
Size  
Qty Natural Gas  
Propane Gas  
pilot is cleaned, blow  
any dirt away with  
compressed air. The  
combination valve  
includes a pilot ad-  
justment screw. To  
adjust, remove cap  
screw and adjust the  
Drill Size P/N Drill Size P/N  
75  
4
4
5
5
6
7
8
9
45  
41  
41  
38  
38  
38  
38  
39  
39  
39  
39  
38678 1.2 mm 63003  
11792 1.45 mm 61652  
11792 1.45 mm 61652  
45870 1.55 mm 61653  
45870 1.55 mm 61653  
45870 1.55 mm 61653  
45870 1.55 mm 61653  
45871 1.55 mm 61653  
100  
125  
140  
170  
200  
225  
250  
300  
350  
400  
Figure 21 - Pilot Burner Spark Gap  
pilot flame to ap-  
proximately 1-1/4".  
Pilot System - No periodic maintenance of the ignition control box  
is required. However, each season the lead wires should be checked for  
insulation deterioration and good connections. Proper operation of the  
electronic spark ignition system requires a minimum flame signal of  
0.2 microamps as measured by a microampmeter. Do not attempt to  
11  
13  
15  
45871  
45871  
45871  
53  
53  
53  
9789  
9879  
9879  
NOTE: Use only factory-authorized replacement parts.  
Form 421, Page 22  
Download from Www.Somanuals.com. All Manuals Search And Download.  
All Sizes 75, 100 and 125 (do not have heat exchanger "V" baffles)  
and Sizes 140-400 manufactured prior to 11/95 (do not have heat  
exchanger "V" baffles) -- Remove the burner rack assembly. Use a  
furnace brush (or a piece of heavy wire to which a piece of steel wool  
is attached). Brush up and down within the tubes until all soot is re-  
moved. With an air hose or brush, clean the outside space between the  
lower portions of the heat exchanger tubes to remove any accumulated  
dust or light deposits.  
30. Cleaning the Heat Exchanger  
CAUTION: When cleaning, wearing eye  
protection is recommended.  
Outer Surfaces (circulating air side) - To clean the outer sur-  
faces of the heat exchanger, gain access by removing the inspection  
panels in the ductwork or remove the ductwork. Depending on whether  
or not the furnace is designed for high CFM (Model prefix "H"), there  
may be directional baffles between the heat exchanger tubes. The stan-  
dard furnace has baffles between the heat exchanger tubes as shown in  
Figure 3B, page 5. (High CFM furnaces have only the top baffle sup-  
port which does not need to be removed for cleaning.)  
Sizes 140 - 400 manufactured beginning 11/95 (have heat exchanger  
"V" baffles) -- Remove the burner rack assembly. Make sure that the  
flue pipe is supported. Remove the three screws that attach the venter  
housing to the outlet duct (pipe from furnace to venter). The venter  
assembly will remain in place. Remove the six screws used to attach  
the flue collection box to the top of the furnace. Remove the flue col-  
lection box exposing the heat exchanger tubes. The V-shaped tube  
baffles can now be removed.  
To remove the baffles, remove the screws marked "A" in Figure 3B,  
and slide each baffle forward. Use a brush and/or an air hose to remove  
accumulated dust and grease deposits from the heat exchanger tubes  
and the baffles. Re-install the baffles by sliding them into the rear slot  
and replacing the screw. Secure ductwork as necessary.  
All Sizes -- After cleaning is complete, reverse the procedure to re-  
assemble the furnace. Use extreme care so that no unsafe conditions  
are created. Check the furnace for proper operation.  
Inner Surfaces (combustion gas side) - The inner surfaces of the  
heat exchanger can be reached for cleaning with the burner rack re-  
moved (See Paragraph 28.) An air hose; a long (18 to 24-inch), 1/2"  
diameter stiff brush; a flashlight; and a mirror are needed. The required  
procedure depends on the size of the furnace and the date of manufac-  
ture. Follow these instructions to clean the inner surfaces of the heat  
exchanger.  
31. Venter  
Motor - Remove dirt from the outer surface. The venter motor is per-  
manently lubricated; no oiling is required.  
Venter Relay - The venter relay controls the venter motor. If relay  
contacts fail to "make", the venter motor will not run. If relay contacts  
fail to "open, the venter motor will not shut off.  
32. Troubleshooting  
TROUBLE  
PROBABLE CAUS E  
REMEDY  
No power to unit.  
Turn on power, check supply fuses, or circuit breaker.  
Turn up thermostat; check control transformer output. Check for loose wire connections.  
Replace relay.  
Replace motor or capacitor.  
Open manual valve.  
Venter  
motor will  
not start  
1.  
2.  
3.  
4.  
1.  
2.  
3.  
4.  
5.  
6.  
7.  
a)  
b)  
c)  
d)  
e)  
f)  
1.  
2.  
3.  
4.  
1.  
2.  
3.  
4.  
5.  
6.  
7.  
a)  
b)  
c)  
d)  
e)  
f)  
No 24 volt power to venter relay.  
Venter relay defective.  
Defective motor or capacitor.  
Manual valve not open.  
Air in gas line.  
Dirt in pilot orifice.  
Gas pressure too high or too low.  
Kinked pilot tubing.  
Pilot valve does not open.  
No spark:  
Loose wire connections  
Transformer failure.  
Pilot will  
not light  
(venter  
Bleed gas line.  
Remove and clean with compressed air or solvent (do not ream).  
Adjust supply pressure. (See Paragraph 9).  
Replace tubing.  
operating)  
If 24 volt available at valve, replace valve.  
Be certain all wires connections are solid.  
Be certain 24 volts is available.  
Maintain spark gap at .100".  
Replace worn or grounded spark cable.  
Replace pilot if ceramic spark electrode is cracked or grounded.  
Make sure all panels are in place and tightly secured to prevent drafts at pilot.  
Make certain ignition control is grounded to furnace chassis  
If 24 volt is available to ignition controller and all other causes have been eliminated,  
Incorrect spark gap.  
Spark cable shorted to ground.  
Spark electrode shorted to ground.  
Drafts affecting pilot.  
Ignition control not grounded.  
Faulty ignition controller.  
g)  
h)  
g)  
h)  
replace ignition control.  
Optional lockout device interrupting Reset lockout by interrupting control at thermostat.  
8.  
9.  
8.  
Faulty combustion air proving  
Manual valve not open.  
Main valve not operating.  
Defective valve.  
Replace combustion air proving switch.  
Open manual valve.  
9.  
1.  
2.  
a)  
b)  
Pilot lights, 1.  
main valve 2.  
will not open a)  
b)  
If 24 volt is measured at valve connections and valve remains closed, replace valve.  
Check and tighten all wiring connections.  
Loose wire connections.  
(Troubleshooting is continued on page 24.)  
RGM Form 421, Mfg No. 150492, Page 23  
Download from Www.Somanuals.com. All Manuals Search And Download.  
32. Troubleshooting (cont'd)  
TROUBLE (cont'd) PROBABLE CAUSE (cont'd)  
REMEDY (cont'd)  
3.  
Ignition control does not power main valve.  
Pilot lights, main  
3.  
valve will not open  
(cont'd)  
Loose wire connections.  
Flame sensor grounded. (Pilot lights - spark  
Check and tighten all wiring connections.  
Be certain flame sensor lead is not grounded or insulation or  
a)  
b)  
a)  
b)  
continues)  
ceramic is not cracked. Replace as required.  
Set supply pressure at 5" w.c. to 14" w.c. for natural gas and  
Gas pressure incorrect.  
c)  
c)  
11" w.c. to 14" w.c. for propane gas.  
Cracked ceramic at sensor.  
Faulty ignition controller.  
Replace sensor.  
If all checks indicate no other cause, replace ignition  
d)  
e)  
d)  
e)  
controller. Do not attempt to repair ignition controller; it has no  
field replaceable components.  
Dirty Filters  
Incorrect manifold pressure or orifices.  
Clean or replace filters.  
Check manifold pressure (See Paragraph 9).  
No heat (Heater  
Operating)  
1.  
2.  
1.  
2.  
Cycling on limit control.  
Improper thermostat location or adjustment. See thermostat manufacturer's instructions.  
4.  
Belt slipping on blower.  
Fan control improperly located or adjusted.  
Defective fan control.  
Blower set for too low temprrature rise.  
Incorrect manifold pressure.  
Circuit open.  
Check air throughput (See Paragraph 15).  
3.  
4.  
5.  
3.  
Adjust belt tension.  
Relocate or adjust fan control (See Paragraph 19).  
Replace fan control.  
Slow down blower or increase static pressure..  
Check manifold line pressure (See Paragraph 9).  
Check wiring and connections.  
Replace fan control.  
Replace motor or capacitor.  
Relocate or adjust fan control (See Paragraph 19).  
Replace fan control.  
Check motor load against motor rating plate. Replace motor  
5.  
1.  
2.  
3.  
4.  
1.  
2.  
3.  
1.  
2.  
3.  
Cold air delivered 1.  
On Start-up 2.  
During Operation 3.  
4.  
Motor will not run 1.  
2.  
Fan control inoperative.  
Defective motor or capacitor.  
Fan control improperly located or adjusted.  
Defective fan control.  
3.  
Motor turns on and 1.  
off while burner is 2.  
Motor overload device cycling on and off.  
operating (See  
3.  
if needed.  
"Motor... " below)  
3 phase motor rotating in opposite  
Improper motor pulley and/or adjustment.  
Interchange 2 legs on supply connections.  
See instructions on air throughput.  
4.  
4.  
1.  
Blower motor cuts 1.  
Improper static pressure in the duct system. Adjust duct system dampers.  
2.  
out on overload  
2.  
Low voltage.  
Check power supply.  
3.  
3.  
FOR SERVICE OR REPAIR, FOLLOW THESE STEPS IN ORDER:  
FIRST:  
Contact the installer.  
Name  
_______________________________________________________________________________________  
Address ________________________________________________________________________________________  
________________________________________________________________________________________  
________________________________________________________________________________________  
Phone ________________________________________________________________________________________  
SECOND:  
THIRD:  
Contact the nearest distributor (See telephone Yellow Pages.)  
Contact:  
REZNOR®, Thomas & Betts Corporation  
150 McKinley Avenue  
Mercer, PA 16137  
Phone: (724) 662-4400  
Model No. _______________________________________  
Unit Serial No. ___________________________________  
Date of Installation ________________________________  
©2000 Thomas & Betts Corporation, All rights reserved.  
Printed in the U.S.A.  
MANUFACTURER OF GAS, OIL, ELECTRIC HEATING AND VENTILATING SYSTEMS  
Trademark Note: Reznor® is registered in the United States and other countries.  
3/00 YL Form 421-A.5  
Form 421, Page 24  
Download from Www.Somanuals.com. All Manuals Search And Download.  

Texas Instruments Calculator Avigo User Manual
Toshiba Portable DVD Player SDP63SWE User Manual
Tricity Bendix Cooktop CSE551 User Manual
Tricity Bendix Kitchen Entertainment Center BR593W User Manual
Trimble Outdoors GPS Receiver 64057 00 ENG User Manual
Uniden Car Satellite Radio System Bearcat 880 User Manual
Universal Remote Control Universal Remote TKP 2000 User Manual
Viking Appliance Trim Kit F20713 User Manual
VTech Telephone BS5822 User Manual
Waring Coffeemaker CU 55 User Manual