58MXA
4-Way Multipoise Fixed-Capacity
Direct-Vent Condensing Gas Furnace
Service and Maintenance Instructions
→ For Sizes 040—140, Series 130
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A93040
CANADIAN GAS ASSOCIATION
A PPROVED
R
NOTE: Read the entire instruction manual before performing any
service or maintenance.
This symbol → indicates a change since the last issue.
Index
Page
As an ENERGY STAR®
Partner, Carrier Corporation
has determined that this prod-
uct meets the ENERGY
STAR® guidelines for energy
efficiency.
SAFETY CONSIDERATIONS..................................................1-2
ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS........2
GENERAL......................................................................................2
CARE AND MAINTENANCE................................................2-11
Cleaning and/or Replacing Air Filter.......................................3
Blower Motor and Wheel Maintenance................................3-4
Cleaning Burners...................................................................4-5
Cleaning Heat Exchangers ....................................................5-7
Primary Heat Exchangers ................................................5-7
Secondary Heat Exchangers................................................7
Flushing Collector Box and Drainage System ........................7
Servicing Hot Surface Ignitor...............................................7-8
Electrical Controls and Wiring.................................................8
Troubleshooting................................................................8-9-10
Checking Heat Tape Operation (If Applicable) ....................10
Winterizing ........................................................................10-11
WIRING DIAGRAM...................................................................12
SERVICE LABEL .......................................................................13
TROUBLESHOOTING GUIDE ............................................14-15
A93007
REGISTERED QUALITY SYSTEM
Fig. 1—Multipoise Furnace in Upflow Orientation
.2-M95 National Standard of Canada, Natural Gas and Propane
Installation Codes (NSCNGPIC). Wear safety glasses and work
gloves. Have a fire extinguisher available during start-up and
adjustment procedures and service calls.
Recognize safety information. This is the safety-alert symbol
.
When you see this symbol on the unit and in instructions or
manuals, be alert to the potential for personal injury.
SAFETY CONSIDERATIONS
Installing and servicing heating equipment can be hazardous due to
gas and electrical components. Only trained and qualified person-
nel should install, repair, or service heating equipment.
Understand the signal words DANGER, WARNING, and CAU-
TION. These words are used with the safety-alert symbol. DAN-
GER identifies the most serious hazards which will result in severe
personal injury or death. WARNING signifies hazards which
could result in personal injury or death. CAUTION is used to
identify unsafe practices which would result in minor personal
injury or product and property damage. NOTE is used to highlight
suggestions which will result in enhanced installation, reliability,
or operation.
Untrained personnel can perform basic maintenance functions
such as cleaning and replacing air filters. All other operations must
be performed by trained service personnel. When working on
heating equipment, observe precautions in the literature, on tags,
and on labels attached to or shipped with the unit and other safety
precautions that may apply.
Follow all safety codes. In the United States, follow all safety
codes including the National Fuel Gas Code (NFGC) NFPA
54-1996/ANSI Z223.1-1996 and the Installation Standards, Warm
Air Heating and Air Conditioning Systems (NFPA 90B)
ANSI/NFPA 90B. In Canada, refer to the CAN/CGA-B149.1- and
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book
Tab 6a 8a
1
4
PC 101
Catalog No. 535-745
Printed in U.S.A.
Form 58MXA-6SM
Pg 1
5-99
Replaces: 58MXA-5SM
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WASHABLE
FILTER
FILTER
RETAINER
WASHABLE
FILTER
FILTER
RETAINER
FILTER
SUPPORT
A93046
A93045
Fig. 3—Bottom Filter Arrangement
Fig. 4—Filter Installed for Side Inlet
Step 1—Cleaning and/or Replacing Air Filter
All factory wires can be left connected, but field thermostat
connections may need to be disconnected depending on their
length and routing.
The air filter arrangement may vary depending on the application
or orientation.
4. Position control box, transformer, and door switch assembly to
right side of furnace casing.
5. If condensate trap is located in left- or right-hand side of
furnace casing, proceed to item 6, otherwise remove trap and
tubing as described below.
Never operate unit without a filter or with the blower access
panel removed. Failure to follow this warning could result in
a fire or personal injury.
a. Disconnect field drain connection from condensate trap.
b. Disconnect drain and relief port tubes from condensate
trap.
To clean or replace the filters, proceed as follows:
1. Turn off electrical supply to furnace.
c. Remove condensate trap from blower shelf.
2. Remove main furnace door and blower access panel.
3. Release filter retainer wire. (See Fig. 3 and 4.)
4. Slide filter out of furnace.
6. Remove screws securing blower assembly to blower shelf and
slide blower assembly out of furnace.
7. Clean blower wheel and motor by using a vacuum with soft
brush attachment. Be careful not to disturb balance weights
(clips) on blower wheel vanes. Do not bend wheel or blades as
balance will be affected.
5. Furnaces are equipped with permanent, washable filter(s).
Clean filter by spraying cold tap water through filter in
opposite direction of airflow.
6. Rinse filter and let dry. Oiling or coating of filter is not
recommended.
8. If greasy residue is present on blower wheel, remove wheel
from the blower housing and wash it with an appropriate
degreaser. To remove wheel:
7. Place filter in furnace.
a. Mark blower wheel location on shaft before disassembly to
ensure proper reassembly.
8. Replace blower access panel and main furnace door.
9. Turn on electrical supply to furnace.
b. Loosen setscrew holding blower wheel on motor shaft.
NOTE: Mark blower mounting arms and blower housing so each
arm is positioned at the same hole location during reassembly.
NOTE: If the filter has cross-mesh binding, the binding must face
the blower. If the filter has an air direction arrow, the arrow must
point toward the blower.
c. Mark blower wheel orientation and cutoff plate location to
ensure proper reassembly.
Step 2—Blower Motor and Wheel Maintenance
d. Remove screws securing cutoff plate and remove cutoff
plate from housing.
To ensure long life, economy, and high efficiency, clean accumu-
lated dirt and grease from blower wheel and motor annually.
e. Remove bolts holding motor mounts to blower housing and
slide motor and mounts out of housing. Disconnect capaci-
tor and ground wire attached to blower housing before
removing motor.
The inducer and blower motors are pre-lubricated and require no
additional lubrication. These motors can be identified by the
absence of oil ports on each end of the motor.
The following items should be performed by a qualified service
technician.
f. Remove blower wheel from housing.
g. Clean wheel per instructions on degreaser cleaner.
Clean blower motor and wheel as follows:
1. Turn off electrical supply to furnace.
2. Remove main furnace door and blower access panel.
3. Disconnect wires.
9. Reassemble motor and blower wheel by reversing items 8b
through 8f. Ensure wheel is positioned for proper rotation. Be
sure to reattach ground wire.
10. Reinstall blower assembly in furnace.
3
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11. Reinstall condensate trap and tubing if previously removed.
a. Reinstall condensate trap in hole in blower shelf.
5. Remove wires from gas valve. Note location for reassembly.
b. Connect condensate trap drain tubes. See Fig. 8 or tubing
diagram on main furnace door for proper tube location.
Label all wires prior to disconnection when servicing con-
trols. Wiring errors can cause improper and dangerous
operation.
(1.) Connect 1 tube (blue or blue and white striped) from
collector box.
(2.) Connect 1 tube (violet or unmarked) from inducer
housing.
6. Remove burner box pressure tube from gas valve regulator
fitting.
(3.) Connect 1 tube (relief port, green or pink) from
collector box.
7. Remove screws that secure manifold to burner box. (See Fig.
5.)
c. Connect field drain to condensate trap.
NOTE: Ensure tubes are not kinked or pinched, as this will affect
operation.
MANIFOLD
MOUNTING
SCREW
12. Reinstall control box, transformer, and door switch assembly
on blower shelf.
13. Reconnect wires.
Refer to furnace wiring diagram, and connect thermostat leads
if previously disconnected. (See Fig. 15.)
NOTE: Refer to Table 1 for motor speed lead relocation if leads
were not identified before disconnection.
Table 1—Speed Selector
FACTORY
ATTACHED TO
COLOR
SPEED
Black
High
Medium High
Medium Low
Low
Cool
MANIFOLD
Yellow (When Present)
Spare
Blue
Red
Heat
GAS VALVE
REGULATOR
FITTING
Spare
White
Common
Com
GAS VALVE
A93295
Fig. 5—Burner Box Assembly
Heating speed selection MUST be adjusted to provide proper
temperature rise as specified on the rating plate. Failure to
adjust the heating speed may shorten heat exchanger life.
8. Remove manifold, orifices, and gas valve as 1 assembly.
9. Remove screws attaching burner assembly in burner box.
10. Remove burner assembly from burner box.
14. Turn on electrical supply. Manually close blower access panel
door switch. Use a piece of tape to hold switch closed. Check
for proper rotation and speed changes between heating and
cooling by jumpering R to G and R to Y on control center
thermostat terminals. (See Fig. 12.)
NOTE: All burners are attached to burner bracket and can be
removed as 1 assembly.
11. Clean burners with soft brush and vacuum.
12. Reinstall manifold, orifice, and gas valve assembly in burner
box. Ensure manifold seal grommet is installed properly and
burners fit over orifices.
Blower access panel door switch opens 115-v power to
control center. No component operation can occur. Caution
must be taken when manually closing this switch for service
purposes. Failure to follow this warning could result in
personal injury or death.
13. Reconnect wires to gas valve. Refer to furnace wiring diagram
for proper wire location.
14. Reinstall burner box pressure tube to gas valve regulator
fitting.
15. Reinstall gas supply pipe to gas valve using backup wrench on
gas valve to prevent rotation and improper orientation.
15. If furnace is operating properly, release blower access panel
door switch, replace blower access panel, and replace main
furnace door.
NOTE: Use propane gas resistant pipe dope to prevent gas leaks.
DO NOT use Teflon tape.
Step 3—Cleaning Burners
The following items should be performed by a qualified service
technician. If the burners develop an accumulation of light dirt or
dust, they may be cleaned by using the following procedure:
Gas valve switch or knob MUST be facing forward or tilted
upward. Failure to follow this warning could result in
property damage, personal injury, or death.
1. Turn off gas and electrical supplies to furnace.
2. Remove main furnace door.
16. Replace burner box cover.
3. Remove burner box cover.
17. Turn on gas and electrical supplies to furnace.
18. Check for gas leaks.
4. Using backup wrench, disconnect gas supply pipe from gas
valve.
4
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PRIMARY HX
INLET OPENINGS
Never use matches, candles, flame, or other sources of
ignition to check for gas leakage. Use a soap-and-water
solution. Failure to follow this warning could result in a fire,
personal injury, or death.
19. Replace main furnace door.
Step 4—Cleaning Heat Exchangers
The following items should be performed by a qualified service
technician.
PRIMARY HEAT EXCHANGERS
If the heat exchangers get an accumulation of light dirt or dust on
the inside, they may be cleaned by the following procedure:
NOTE: If the heat exchangers get a heavy accumulation of soot
and carbon, both the primary and secondary heat exchangers
should be replaced rather than trying to clean them thoroughly due
to their intricate design. A build-up of soot and carbon indicates
that a problem exists which needs to be corrected, such as
improper adjustment of manifold pressure, insufficient or poor
quality combustion air, improper vent termination, incorrect size
or damaged manifold orifice(s), improper gas, or a restricted heat
exchanger (primary or secondary). Action must be taken to correct
the problem.
A93080
Fig. 6—Cleaning Inlet Openings of Primary Heat
Exchangers
NOTE: Inspect combustion-air intake housing. If foamed gasket
was removed, check for any damage. If gasket is damaged in any
way, it must be repaired. To repair, remove damaged gasket
section, apply sealant releasing agent such as PAM cooking spray
or equivalent (must not contain corn or canola oil, aromatic or
halogenated hydrocarbons or inadequate seal may occur) to burner
box and apply a small bead of G.E. RTV 162. G.E. RTV 6702, or
Dow-Corning RTV 738 sealant to edge of combustion-air intake
housing. (See Fig. 7.)
1. Turn off gas and electrical supplies to furnace.
2. Remove main furnace door.
3. Disconnect wires or connectors to rollout switch, gas valve,
ignitor, and flame sensor.
Label all wires prior to disconnection when servicing con-
trols. Wiring errors can cause improper and dangerous
operation.
4. Disconnect combustion-air intake pipe from intake housing.
5. Remove the pressure switch tube from intake housing.
RTV
6. Remove screws attaching intake housing to burner box, and
rotate intake housing away from burner box for removal.
7. Using backup wrench, disconnect gas supply pipe from gas
valve.
PAM
8. Disconnect pressure tubing from gas valve.
9. Remove 2 screws attaching top filler panel and rotate upwards
to gain access to screws attaching burner box to cell panel.
A93087
Fig. 7—Combustion-Air Intake Housing Gasket
Repair
10. Remove screws attaching burner box to cell panel. (See Fig.
5.)
NOTE: Burner box cover, manifold, gas valve, and burner
assembly should be removed as 1 assembly.
13. Refer to furnace wiring diagram and reconnect wires to rollout
switch, gas valve, ignitor, and flame sensor.
14. Reconnect pressure switch tubes to gas valve and intake
housing. Refer to tube routing label on main furnace door for
proper tube location. Be sure tubes are not kinked. (See Fig.
8.)
11. Clean heat exchanger openings with a vacuum and a soft
brush. (See Fig. 6.)
NOTE: After cleaning, inspect the heat exchangers to ensure they
are free of all foreign objects that may restrict flow of combustion
products.
15. Turn on gas and electrical supplies to furnace.
16. Check furnace operation through 2 complete heat operating
cycles. Look through sight glass in burner enclosure to check
burners. Burner flames should be clear blue, almost transpar-
ent. (See Fig. 9.)
12. Reverse items 4 through 10 for reassembly.
17. Check for gas leaks.
The ground wire from the gas valve MUST be attached to the
burner box attachment screw. Failure to attach this ground
wire to an adequate casing ground will cause the furnace
control to lock out.
NOTE: Be sure burner box gasket is installed between burner box
and cell panel. If gasket is damaged, replace it.
5
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TUBE ROUTING
Furnace is shipped from factory in upflow configuration. Pressure tube and drain tube routing MUST match the diagrams below.
Condensate Trap on LEFT
Condensate Trap; Factory Installed
Tube location when used in UPFLOW application
Side Optional
in Blower Shelf
BURNER ENCLOSURE
PRESSURE REFERENCE
TUBE ASSEMBLY
BURNER ENCLOSURE
PRESSURE REFERENCE
TUBE ASSEMBLY
(Blower access panel removed)
CAP
CAP
COLLECTOR BOX TUBE
(PINK)
PLUG
PLUG
COLLECTOR BOX TUBE
COLLECTOR BOX TUBE
(GREEN)
(PINK)
COLLECTOR BOX DRAIN
TUBE
COLLECTOR BOX TUBE (GREEN)
(BLUE & WHITE STRIPED)
COLLECTOR BOX DRAIN TUBE
(BLUE & WHITE STRIPED)
INDUCER HOUSING (MOLDED) DRAIN TUBE
(BEHIND COLLECTOR BOX DRAIN TUBE)
CONDENSATE TRAP
COLLECTOR BOX DRAIN TUBE
(BLUE)
COLLECTOR BOX DRAIN TUBE
(BLUE)
FIELD-INSTALLED
FACTORY-SUPPLIED
DRAIN TUBE COUPLING
(RIGHT DRAIN OPTION)
CONDENSATE TRAP
FIELD-INSTALLED
FACTORY-SUPPLIED DRAIN TUBE
COUPLING (LEFT DRAIN OPTION)
INDUCER HOUSING DRAIN TUBE
(VIOLET)
FIELD-INSTALLED
FACTORY-SUPPLIED 1/2-IN.
CPVC STREET ELBOWS (2)
FOR LEFT DRAIN OPTION
FIELD-INSTALLED FACTORY-SUPPLIED
DRAIN TUBE
Condensate Trap on
LEFT Side
Condensate Trap on
RIGHT Side
Tube location when used in DOWNFLOW application
PLUG
COLLECTOR BOX
DRAIN TUBE (BLUE)
PLUGGED END
CAP
CAP
COLLECTOR BOX DRAIN TUBE
(BLUE)
COLLECTOR BOX DRAIN
TUBE
(BLUE & WHITE STRIPED)
COLLECTOR BOX
TUBE (GREEN)
COLLECTOR BOX TUBE
(PINK)
PLUG
COLLECTOR BOX DRAIN TUBE
(BLUE & WHITE STRIPED)
COLLECTOR BOX TUBE
(GREEN)
INDUCER HOUSING DRAIN
TUBE (VIOLET)
COLLECTOR BOX
EXTENSION TUBE
COLLECTOR BOX EXTENSION TUBE
BURNER ENCLOSURE PRESSURE
REFERENCE TUBE ASSEMBLY
COLLECTOR BOX
EXTENSION TUBE
CONDENSATE TRAP
DRAIN TUBE COUPLING
CONDENSATE TRAP
COLLECTOR BOX
TUBE (PINK)
BURNER ENCLOSURE PRESSURE
REFERENCE TUBE ASSEMBLY
DRAIN TUBES ROUTED IN
FRONT OF GAS VALVE
COLLECTOR BOX
EXTENSION DRAIN TUBE
GAS VALVE
INDUCER HOUSING DRAIN TUBE (VIOLET)
Tube location when used on
HORIZONTAL - LEFT application
Tube location when used on
HORIZONTAL - RIGHT application
AUXILIARY "J" BOX RELOCATED HERE
COLLECTOR BOX DRAIN TUBE
(BLUE)
COLLECTOR BOX DRAIN TUBE
(BLUE & WHITE STRIPED)
COLLECTOR BOX EXTENSION TUBE
COLLECTOR BOX TUBE (PINK)
PLUG
CAP
PLUG
COLLECTOR BOX
TUBE (GREEN)
BURNER ENCLOSURE
PRESSURE REFERENCE
TUBE ASSEMBLY
INDUCER HOUSING
DRAIN TUBE
(VIOLET)
CAP
COLLECTOR BOX
EXTENSION TUBE
BURNER ENCLOSURE
PRESSURE REFERENCE
TUBE ASSEMBLY
COLLECTOR BOX
DRAIN TUBE (BLUE)
CONDENSATE TRAP
COLLECTOR BOX
EXTENSION TUBE
COLLECTOR BOX
TUBE (GREEN)
DRAIN TUBE
COUPLING
COLLECTOR BOX TUBE (PINK)
RELOCATE TUBE BETWEEN BLOWER
SHELF AND INDUCER HOUSING FOR
040,060, AND 080 HEATING INPUT
FURNACES
COLLECTOR BOX EXTENSION DRAIN TUBE
COLLECTOR BOX DRAIN TUBE
(BLUE AND WHITE STRIPED)
CONDENSATE TRAP
INDUCER HOUSING DRAIN TUBE (VIOLET)
NOTE:
1. All tubing must be connected securely and routed to avoid kinks and traps.
2. Pressure tubing must always slope away from pressure switch to collector box connection as shown.
3. HORIZONTAL-LEFT installations require the collector box pressure tube to be relocated between the inducer housing and the blower shelf to
prevent a trap. Refer to the Installation Instructions for further details.
324999-201 REV. A
(LIT. BOTTOM)
A99102
→ Fig. 8—Furnace Pressure and Drain Tubing Diagram
BURNER FLAME
BURNER
Never use matches, candles, flame, or other sources of
ignition to check for gas leakage. Use a soap-and-water
solution. Failure to follow this warning could result in a fire,
personal injury, or death.
18. Replace main furnace door.
SECONDARY HEAT EXCHANGERS
NOTE: The condensing side (inside) of the secondary heat
exchangers CANNOT be serviced or inspected. A small number of
bottom outlet openings can be inspected by removing the inducer
assembly. See Flushing Collector Box and Drainage System
section for details on removing inducer assembly.
Step 5—Flushing Collector Box and Drainage
System
MANIFOLD
A89020
1. Turn off gas and electrical supplies to furnace.
2. Remove main furnace door.
Fig. 9—Burner Flame
3. Disconnect inducer motor and pressure switch wires or
connectors.
6
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4. Disconnect pressure switch tubes.
14. Check furnace operation through 2 complete heat operating
cycles. Check area below inducer housing, vent pipe, and
condensate trap to ensure no condensate leaks occur. If leaks
are found, correct the problem.
→ 5. Disconnect vent pipe from inducer housing outlet by loosen-
ing coupling clamp on inducer outlet.
6. Disconnect drain tube from inducer housing. (See Fig. 8.)
15. Check for gas leaks.
7. Remove inducer housing assembly by removing 4 bolts
attaching assembly to cell panel.
8. Flush inside of collector box with water until discharge from
condensate trap is clean and runs freely.
Never use matches, candles, flame, or other sources of
ignition to check for gas leakage. Use a soap-and-water
solution. Failure to follow this warning could result in a fire,
personal injury, or death.
NOTE: Ensure the drain tube disconnected from the inducer
housing is higher than the collector box opening or water will flow
out tube.
16. Replace main furnace door.
9. Inspect inside area of collector box for any pieces of foreign
materials and remove if present.
Step 6—Servicing Hot Surface Ignitor
The ignitor does NOT require annual inspection. Check ignitor
resistance before removal.
DO NOT use wire brush or other sharp object to inspect or
dislodge materials in secondary heat exchangers as failure of
the secondary heat exchanger will occur. Flush with water
only.
1. Turn off gas and electrical supplies to furnace.
2. Remove main furnace door.
3. Disconnect ignitor wire connection.
4. Check ignitor resistance.
→ 10. Reassemble inducer assembly by reversing items 5 through 7.
Tighten the vent coupling clamp screw(s) to 15 in.-lb. of
torque.
a. Using an ohm meter, check resistance across both ignitor
leads in connector.
b. Cold reading should be between 45 ohms and 90 ohms.
NOTE: If seal between the inducer housing and the collector box
is damaged in any way, it must be repaired. To repair, apply
sealant releasing agent such as PAM cooking spray or equivalent
(must not contain corn or canola oil, aromatic or halogenated
hydrocarbons or inadequate seal may occur) to inducer housing.
(See Fig. 10.) Apply a small bead of G.E. RTV 162, G.E. RTV
6702, or Dow-Corning RTV 738 sealant to groove in collector
box.
c. If ohm reading is higher than 110 ohms, ignitor is cracked
and must be replaced.
5. Remove ignitor assembly.
Allow ignitor to cool before removal. Normal operation
temperatures exceed 2000°F.
a. Do not remove ignitor from bracket while assembly is in
furnace. Using a 1/4 in. nutdriver, remove screw securing
bracket and ignitor assembly to bottom of burner box. The
screw in the bracket is always located toward outside of
burner box. The screw may be hidden by inlet box or inlet
pipe, but can be removed without removing either. After
removing screw, slide ignitor and bracket toward outside of
burner box and pull straight out.
PAM
RTV
The ignitor is fragile. DO NOT allow it to hit the side of the
burner box opening while removing or replacing it.
b. Inspect ignitor for a white area indicating a crack may be
present. If found, replace ignitor.
NOTE: A small crack cannot be seen on a new ignitor. After a
period of operation, a white area will be visible around the crack.
c. If replacement is required, replace ignitor on ignitor bracket
external to furnace to avoid damage as the silicon portion is
very brittle and will easily crack or shatter.
d. To remove ignitor from ignitor bracket, remove screw
holding ignitor ceramic block to bracket and pull ceramic
block out of bracket.
A93081
Fig. 10—Gasket on Collector Box
6. To replace ignitor/ignitor assembly, reverse items 5a through
5d.
11. Refer to furnace wiring diagram and reconnect wires to
inducer motor and pressure switch or connectors.
7. Reconnect ignitor wire connection.
12. Reconnect pressure tubes to pressure switch. See diagram on
main furnace door for proper location of tubes. Be sure tubes
are not kinked. (See Fig. 8.)
8. Turn on gas and electrical supplies to furnace.
9. Verify ignitor operation by initiating control board self-test
feature or by cycling thermostat.
13. Turn on gas and electrical supplies to furnace.
7
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10. Replace main furnace door.
The control center stores 1 status code (representing the last fault
to occur) for a period of 48 hr or until the 115- or 24-v power is
interrupted.
Step 7—Electrical Controls and Wiring
NOTE: Removing blower access panel will open blower access
panel door switch and terminate 115-v power to control center.
The status code will be erased. Look into blower access panel sight
glass for current LED status BEFORE removing blower access
panel.
There may be more than 1 electrical supply to the unit. Check
accessories and cooling unit for additional electrical supplies.
The electrical ground and polarity for 115-v wiring must be
maintained properly. Refer to Fig. 11 for field wiring information
and to Fig. 15 for unit wiring information.
The unit’s component test is a useful troubleshooting tool since it
displays the current status code of the furnace and functionally
operates all furnace components except the gas valve. The com-
ponent test and methods to initiate it are described below.
NOTE: If the polarity is not correct, the STATUS LED on the
control center will flash rapidly and prevent the furnace from
operating. The control system also requires an earth ground for
proper operation of the control center and flame sensing.
COMPONENT TEST SEQUENCE
NOTE: All components are functionally operated except the gas
valve.
The 24-v circuit contains an automotive-type, 3-amp fuse located
on the control center. (See Fig. 12.) Any direct shorts of the 24-v
wiring during installation, service, or maintenance will cause this
fuse to blow. If fuse replacement is required, use ONLY a fuse of
identical size.
When component test is initiated, the following sequence of events
occurs:
1. LED flashes a status code 4 times.
2. Inducer motor starts and continues to run for remainder of
component test.
With power to the unit disconnected, check all electrical connec-
tions for tightness. Tighten all screws on electrical connections. If
any smoky or burned connections are found, disassemble the
connection, clean all parts, strip wire, and reassemble properly and
securely.
3. Hot surface ignitor is energized for 15 sec, then de-energized.
4. Main blower operates at cooling speed for 10 sec, then turns
off.
5. Main blower operates at heating speed for 10 sec, then turns
off.
Reconnect electrical supply to unit and observe unit through 1
complete operating cycle. Electrical controls are difficult to check
without proper instrumentation; if there are any discrepancies in
the operating cycle, contact your dealer and request service.
6. Inducer motor stops.
Component test can be initiated by one of the following proce-
dures.
INITIATING COMPONENT TEST AND RETRIEVING STA-
TUS CODE BY REMOVING MAIN LIMIT SWITCH WIRE
Step 8—Troubleshooting
For an explanation of status codes, refer to service label located on
back of main furnace door or Fig. 16, and the Troubleshooting
Guide.
NOTE: NO thermostat signal may be present at control center
and all blower time delay off periods must be completed.
FIELD 24-V WIRING
FIELD 115-, 208/230-, 460-V WIRING
FACTORY 24-V WIRING
FACTORY 115-, 208/230-, 460-V WIRING
NOTE 5
THERMOSTAT
TERMINALS
W
C
R
G
Y
FIVE
WIRE
FIELD-SUPPLIED
DISCONNECT
THREE-WIRE
HEATING
ONLY
208/230- OR
460-V
THREE PHASE
W/W1
GND
GND
GND
115-V
SINGLE
PHASE
NOTE
3
W2
R
208/230-V
SINGLE
PHASE
G
C
AUXILIARY
J-BOX
115-V
FIELD-SUPPLIED
DISCONNECT
SWITCH
GND
NOTE 1
CONDENSING
UNIT
Y/Y2
TWO WIRE
NOTES:
24-V
TERMINAL
BLOCK
FURNACE
CONTROL
CENTER
1. Connect Y or Y/Y2 terminal as shown for proper cooling operation.
2. Proper polarity must be maintained for 115-v wiring.
3. Use W2 with 2-stage thermostat when zoning.
4. If any of the original wire, as supplied, must be replaced, use
same type or equivalent wire.
5. Some thermostats require a "C" terminal connection as shown.
A98325
Fig. 11—Field Wiring
8
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BLOWER OFF DELAY
ADJUSTMENT SWITCH
24V THERMOSTAT
TERMINALS
G
R
Y
W
Com
24V
TEST/TWIN
HUMIDIFIER TERMINAL
(24-VAC 0.5 AMP MAX)
HUM
LED OPERATION &
STATUS LIGHT
HARNESS CONNECTOR
SEC-1
24V TRANSFORMER SEC-2
SPARE 1
3-AMP FUSE
COOL
HEAT
BLOWER SPEED
SELECTION TERMINALS
SPARE 2
EAC 1 (BLACK)
EAC-ELECTRONIC AIR CLEANER
TERMINALS (115-VAC 1.5 AMP MAX)
115-VAC (L1)
POWER
EAC 2 (WHITE)
115-VAC (L2) NEUTRAL
CONNECTION
SUPPLY
HOT SURFACE
INDUCER MOTOR
CONNECTOR
IGNITOR
CONNECTOR
A93052
Fig. 12—Control Center
1. Leave 115-v power to furnace turned on.
2. Remove main furnace door.
3. Manually close blower access panel door switch. Use a piece
of tape to hold switch closed.
3. Look into blower access panel sight glass for current LED
status.
NOTE: Leave blower access panel installed to maintain power to
control center to view current LED status.
Blower access panel door switch opens 115-v power to
control center. No component operation can occur. Caution
must be taken when manually closing this switch for service
purposes. Failure to follow this warning could result in
electrical shock, personal injury, or death.
4. BRIEFLY remove either wire from the main limit switch until
the LED goes out, then reconnect it.
4. BRIEFLY short (jumper) TEST, 1/4-in. quick-connect termi-
nal on control center (adjacent to the LED diagnostic light)
and the COM terminal on thermostat connection block. (See
Fig. 12.)
Make sure limit switch wire does not contact any metallic
component such as the gas valve. If wire is shorted, 3-amp
fuse on control center will blow.
NOTE: If TEST to COM terminals are jumpered longer than 2 sec,
LED will flash rapidly, and retrieval request will be ignored.
NOTE: If wire to main limit is disconnected longer than 4 sec, the
control senses limit circuit is open. Main blower will start and
retrieval request will be ignored.
5. When above items have been completed, the component test
sequence will occur as described in the Component Test
Sequence section above.
5. When above items have been completed, the component test
sequence will occur as described in the Component Test
Sequence section above.
NOTE: Be sure to record the status code which is flashed 4 times
at start of component test for further troubleshooting.
NOTE: Be sure to record the status code which is flashed 4 times
at start of component test for further troubleshooting.
6. After component test is completed and furnace is operating
properly, release blower access panel door switch, replace
blower access panel, and replace main furnace door.
6. After component test is completed and LED is ON continu-
ously indicating the furnace is ready to operate when a signal
from the thermostat is received, replace main furnace door.
Step 9—Checking Heat Tape Operation (If Applicable)
INITIATING COMPONENT TEST AND RETRIEVING STA-
TUS CODE BY JUMPERING CONTROL TEST TERMINAL
In applications where the ambient temperature around the furnace
is 32°F or lower, freeze protection measures are required. If this
application is where heat tape has been applied, check to ensure it
will operate when low temperatures are present.
1. Remove main furnace door.
2. Remove blower access panel.
9
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1. Check for signs of physical damage to heat tape such as nicks,
cuts, abrasions, gnawing by animals, etc.
2. Check for discolored heat tape insulation. If any damage or
discolored insulation is evident, replace heat tape.
3. Check that heat tape power supply circuit is on.
Step 10—Winterizing
32°F MINIMUM INSTALLED
AMBIENT OR FREEZE
PROTECTION REQUIRED
Freezing condensate left in the furnace will damage the
equipment.
If the furnace will be off for an extended period of time in a
structure where the temperature will drop to 32°F or below,
winterize as follows:
1. Turn off electrical supply to furnace.
2. Remove main furnace door.
3. Disconnect drain tube from inducer housing. (See Fig. 13.)
A93058
4. Insert funnel in drain tube and pour antifreeze, propylene
glycol (RV, swimming pool antifreeze, or equivalent) into
furnace until it is visible at point where condensate enters open
drain. (See Fig. 14.)
If this furnace is installed in an unconditioned space where
the ambient temperatures may be 32°F or lower, freeze
protection measures must be taken.
5. Reconnect drain tube to inducer housing.
6. Replace main furnace door.
Do not use ethylene glycol (Prestone II antifreeze/coolant or
equivalent automotive type). Failure of plastic components
will occur.
NOTE: Heat tape, when used, should be wrapped around the
condensate drain trap and drain line. There is no need to use heat
tape within the furnace casing. Most heat tapes are temperature
activated, and it is not practical to verify the actual heating of the
tape. Check the following:
4
A99118
A99119
→ Fig. 13—Inducer Housing Drain Tube
→ Fig. 14—Funnel in Drain and Antifreeze Running
Through Trap
10
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TO 115VAC FIELD DISCONNECT
SCHEMATIC DIAGRAM
(WHEN USED)
LGPS
SW2
SW1
G
R
NOTE #4
NEUTRAL
PRS
BLOWER
OFF
(NATURAL GAS & PROPANE)
PCB
L1
SEE NOTE #10
Y
GND
EQUIPMENT GROUND
ORN
DELAY
W
COM
HUM
(NOT ON ALL MODELS)
L2
LO
ILK
BLOWER OFF DELAY
SELECTION CHART
SPARE-2
HEAT
MED LO
MED HI
HI
TEST/TWIN
NOTE #6
YEL
L1
LED
90 SEC
135 SEC
180 SEC
225 SEC
BLU
1-M
START
SPARE-1
OL
HI/LO
EAC-2
NOTE #8
BLWR
RED
LS
3-P
GV
2-C
NOTE #5
COOL
COM
RED
CAP-1
IDM
COM
PL1
WHT
3
2
1
FRS
FSE
BLWM
EAC-1
WHT
4
7
6
9
5
8
HSIR
IDR
RED
GRN
BLK
WHT
1
2
1
HSI
GVR
SEC-1
SEC-2
BLU
RED
OL
2
PL5
PR2
PL2
M
AUX
HI/LO
RELAY
1
3
1
3
WHT (COM)
GRN
PR1
TRAN
115VAC
24VAC
24 VAC-3A
FUSE
BRN
BRN
PL4
FU1
BLK (HI)
BRN
PL3
CAP -2
OL
COOL
BLOWER
SPARE-1
YEL (MED HI)
NOTE #8
HSIR IDR BLWR
2
2
SPEED
SELECT
START
BLWM
CAP -1
TEST/TWIN
NOTE #7
FU1
HEAT SPARE-2
EAC-1
BLU (MED LO)
RED (LO)
FRS
LS
SEC-2
L2
BRN
SEC-1
PL3
NOTE #12
PL2
GVR-2
1
2
7
1
VAC
PR1
HUM
120
L1
1
2
EAC-2
COM
3
PR2
R
WHT (COM)
(WHEN USED)
LGPS
WHT
BLK
W
4
CAP -2
2
3
PL4
HSIR
BLWR
HI/LO
1
NOTE #6
PRS
FUSED DISCONNECT
PL1
IDR
GVR
SWITCH (WHEN REQ'D)
PL5
BRN
BRN
IDM
JB
NOTE #4
1
2
WHT
M
WHT
NEUTRAL
L1
ILK
3
2
GRN
BLK
AUX
OL
3-P
GV
BLK
GVR-1
FU2
HSI
GRN
GND
CPU
2-C
GRN
1-M
Y
8
NOTE #5
LEGEND
PL1
9-CIRCUIT CONNECTOR
2-CIRCUIT PCB CONNECTOR
3-CIRCUIT IDM CONNECTOR
3-CIRCUIT IDM EXTENSION CONNECTOR
2-CIRCUIT HSI/PCB CONNECTOR
PRESSURE SWITCH, SPST-(N.O.)
BLOWER OFF DELAY
COMPONENT TEST & TWIN TERMINAL
TRANSFORMER-115VAC/24VAC
G
5
6
PL2
PL3
PL4
PL5
PRS
SW1 & 2
TEST/TWIN
TRAN
FSE
BLWR BLOWER MOTOR RELAY, SPST-(N.O.)
BLWM BLOWER MOTOR
CAP
CPU
CAPACITOR
MICROPROCESSOR AND CIRCUITRY
COM
EAC-1 ELECTRONIC AIR CLEANER CONNECTION (115 VAC 1.5 AMP MAX.)
EAC-2 ELECTRONIC AIR CLEANER CONNECTION (COMMON)
9
NOTES:
FRS
FSE
FU1
FU2
FLAME ROLLOUT SW. -MANUAL RESET, SPST-(N.C.)
FLAME PROVING ELECTRODE
FUSE, 3 AMP, AUTOMOTIVE BLADE TYPE, FACTORY INSTALLED
FUSE OR CIRCUIT BREAKER CURRENT INTERRUPT DEVICE
(FIELD INSTALLED & SUPPLIED)
1. IF ANY OF THE ORIGINAL EQUIPMENT WIRE IS REPLACED USE WIRE RATED FOR 105˚C.
2. INDUCER (IDM) AND BLOWER (BLWM) MOTORS CONTAIN INTERNAL
AUTO-RESET THERMAL OVERLOAD SWITCHES (OL).
3. BLOWER MOTOR SPEED SELECTIONS ARE FOR AVERAGE CONDITIONS, SEE INSTALLATION
INSTRUCTIONS FOR DETAILS ON OPTIMUM SPEED SELECTION.
4. USE ONLY COPPER WIRE BETWEEN THE DISCONNECT SWITCH AND THE
FURNACE JUNCTION BOX (JB).
JUNCTION
UNMARKED TERMINAL
PCB TERMINAL
GND
GV
GVR
EQUIPMENT GROUND
GAS VALVE-REDUNDANT OPERATORS
GAS VALVE RELAY, DPST-(N.O.)
FACTORY WIRING (115VAC)
FACTORY WIRING (24VAC)
FIELD WIRING (115VAC)
FIELD WIRING (24VAC)
CONDUCTOR ON PCB
FIELD WIRING TERMINAL
FIELD EARTH GROUND
EQUIPMENT GROUND
FIELD SPLICE
HI/LO BLOWER MOTOR SPEED CHANGE RELAY, SPDT
HSI HOT SURFACE IGNITOR (115 VAC)
HSIR HOT SURFACE IGNITOR RELAY, SPST-(N.O.)
HUM 24VAC HUMIDIFIER CONNECTION (.5 AMP. MAX.)
5. THIS WIRE MUST BE CONNECTED TO FURNACE SHEETMETAL FOR CONTROL TO PROVE
FLAME.
6. FACTORY CONNECTED WHEN LGPS NOT USED.
7. REPLACE ONLY WITH A 3 AMP FUSE.
IDM
IDR
ILK
JB
INDUCED DRAFT MOTOR
8. YELLOW LEAD NOT ON ALL MOTORS.
INDUCED DRAFT RELAY, SPST-(N.O.)
BLOWER ACCESS PANEL INTERLOCK SWITCH, SPST-(N.O.)
JUNCTION BOX
9. BLOWER-ON DELAY, GAS HEATING 60 SECONDS, COOLING OR HEAT PUMP 2 SECONDS.
10. BLOWER-OFF DELAY, GAS HEATING 90, 135, 180 OR 225 SECONDS, COOLING OR
HEAT PUMP 90 SECONDS. (135 SECONDS ONLY ON SOME MODELS)
11. IGNITION-LOCKOUT WILL OCCUR AFTER FOUR CONSECUTIVE UNSUCCESSFUL
TRIALS-FOR-IGNITION. CONTROL WILL AUTO-RESET AFTER THREE HOURS.
12. SOME MODELS MAY HAVE SPADE QUICK CONNECT TERMINALS.
LED
LIGHT-EMITTING DIODE FOR STATUS CODES
LGPS LOW GAS PRESSURE SWITCH, SPST-(N.O.)
LS
OL
PCB
LIMIT SWITCH, AUTO RESET, SPST(N.C.)
AUTO-RESET INTERNAL MOTOR OVERLOAD TEMP. SW.
PRINTED CIRCUIT BOARD
PLUG RECEPTACLE
322854-101 REV. D (LIT)
A99106
→ Fig. 15—Wiring Diagram
11
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SERVICE
If status code recall is needed, do not remove power or blower door. Briefly remove and then
reconnect one main limit wire to display stored status code.
LED CODE
STATUS
CONTINUO US OFF - C he c k for 115VAC a t L1 a nd L2, a nd 24VAC a t SEC -1 a nd
SEC-2.
CONTINUO US ON -
RAPID FLASHING -
C ontro l ha s 24V p o we r.
Line vo lta g e (115V) p o la rity re ve rse d . If twinne d , re fe r to
twinning kit instruc tio ns.
EACH OF THE FOLLOWING STATUS CODES IS A TWO DIGIT NUMBER WITH THE FIRST
DIGIT DETERMINED BY THE NUMBER OF SHORT FLASHES AND THE SECOND DIGIT BY
THE NUMBER OF LONG FLASHES.
11 NO PREVIOUS CODE - Sto re d sta tus c od e s a re e ra se d w he n p o we r
(115V or 24V) to c o ntro l is inte rrup te d o r 48 ho urs a fte r e a c h fa ult is c le a re d .
12 BLOWER ON AFTER PO WER UP (115V o r 24V) - Blowe r runs for 90 se c on d s,
if unit is p ow e re d up d uring a c a ll fo r he a t (R-W c lo se d ).
13 LIMIT OR FLAME RO LL-OUT SWITCH LOCKOUT - Co ntrol will a uto re se t a fte r
thre e ho urs unle ss fla m e ro ll-o ut switc h o r fuse link is o p e ne d , re fe r to #33.
14 IG NITIO N LO CKO UT - C o ntro l will a uto -re se t a fte r thre e ho urs. Re fe r to #34.
21 G AS HEATING LOCKOUT - C ontro l will NO T a uto re se t.
C he c k fo r: - Mis-wire d g a s va lve
-De fe c tive c o ntro l (va lve re la y)
22 ABNORMAL FLAME-PROVING SIGNAL - Fla m e is p ro ve d while g a s va lve is
d e -e ne rg ize d . Ind uc e r will run until fa ult is c le a re d .
C he c k fo r:
- Le a ky g a s va lve
-Stuc k-op e n g a s va lve
23 PRESSURE SWITCH (ES) DID NO T OPEN C he c k fo r:
- Ob struc te d p re ssure tub ing .
24 SECONDARY VO LTAGE FUSE IS OPEN
- De fe c tive p re ssure switc h (stuc k c lose d ).
C he c k fo r: - Short c irc uit in se c o nd a ry vo lta g e (24V) wiring .
31 PRESSURE, DRAFT SAFEG UARD, AUXILIARY-LIMIT (whe n use d ) , O R BLOCKED
VENT SHUTO FF (whe n use d ) SWITCH DID NOT CLOSE O R REOPENED - If o p e n
long e r tha n five m inute s, ind uc e r shuts o ff fo r 15 m inute s b e fo re re try.
C he c k fo r:
- Ina d e q ua te C o m b ustio n a ir sup p ly.
- Pro p e r ve nt sizing a nd c ond e nsa te p itc h o r sa g
- Lo w ind uc e r volta g e .
- Ve nt re stric tion or hig h wind s.
- Disc onne c te d o r o b struc te d p re ssure tub ing
- De fe c tive ind uc e r m o to r o r sta rt c a p a c ito r.
- De fe c tive p re ssure sw itc h o r c o nne c tio ns. If it o p e ns a fte r tria l fo r ig nitio n
p e rio d , b lo we r will c o m e o n for 90 se c o nd re c yc le d e la y.
33 LIMIT OR FLAME RO LL-OUT SWITCH IS O PEN - If o p e n lo ng e r tha n thre e
m inute s, c o d e c ha ng e s to #13. Fla m e ro ll-o ut switc h re q uire s m a nua l re se t.
C he c k fo r: - De fe c tive b lo we r m o to r o r c a p a c itor.
- Dirty filte r or re stric te d d uc t syste m .
- Lo o se b lo we r whe e l.
- De fe c tive switc h o r c o nne c tio ns.
- Ina d e q ua te Co m b ustio n a ir sup p ly (Fla m e Roll-out Switc h or fuse link).
- Op e n Fla m e Ro ll-out sw itc h,or fuse link. Ma nua l re se t o r re p la c e .
34 IG NITIO N PRO VING FAILURE - C ontro l will try thre e m o re tim e s b e fo re a
loc kout #14 oc c urs. If fla m e sig na l lost a fte r tria l for ig nitio n p e riod , b lowe r
w ill c o m e on fo r 90 se c ond re c yc le d e la y. C he c k for:
- O xid e b uild up o n fla m e se nso r (c le a n w ith fine ste e l wo o l).
- Pro p e r fla m e se nse m ic roa m p s (.5 m ic ro a m p s D.C . m in., 4.0 - 6.0 nom ina l).
- G a s va lve d e fe c tive o r g a s va lve turne d off.
- De fe c tive Ho t Surfa c e Ig nito r
- Ma nua l va lve shut-o ff.
- Lo w inle t g a s p re ssure .
- G re e n wire MUST b e c o nne c te d to furna c e she e t m e ta l.
- Ina d e q ua te fla m e c a rryo ve r or ro ug h ig nition.
COMPONENT TEST
To initia te the c o m p o ne nt te st se q ue nc e ,shut OFF the roo m the rm o sta t o r
d isc o nne c t the "R" the rm o sta t le a d . Brie fly sho rt the TEST te rm ina l to the "Co m
24V" te rm ina l. Sta tus LED will fla sh c o d e a nd the n turn O N the ind uc e r m o tor. The
ind uc e r m oto r will run for the e ntire c o m p o ne nt te st. The ho t surfa c e ig nitor,
b lo we r m o to r-he a t sp e e d , a nd b lo we r m o to r-c o o l sp e e d w ill b e turne d O N for
10-15 se c ond s e a c h. G a s Va lve a nd Hum id ifie r will no t b e turne d o n.
G
Com
24V
Y
W
R
HUM
320615-102 REV. J
A99107
→ Fig. 16—Service Label
12
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14
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15
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SERVICE TRAINING
Packaged Service Training programs are an excellent way to increase your
knowledge of the equipment discussed in this manual, including:
• Unit Familiarization
• Installation Overview
• Maintenance
• Operating Sequence
A large selection of product, theory, and skills programs is available, using popular
video-based formats and materials. All include video and/or slides, plus companion
book.
Classroom Service Training plus "hands-on" the products in our labs can mean
increased confidence that really pays dividends in faster troubleshooting, fewer
callbacks. Course descriptions and schedules are in our catalog.
CALL FOR FREE CATALOG 1-800-962-9212
[ ] Packaged Service Training
[ ] Classroom Service Training
A94328
Copyright 1999 CARRIER Corp. • 7310 W. Morris St. • Indianapolis, IN 46231
58mxa6sm
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book
Tab 6a 8a
1
4
PC 101
Catalog No. 535-745
Printed in U.S.A.
Form 58MXA-6SM
Pg 16
5-99
Replaces: 58MXA-5SM
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