Carrier 58MCB Installation and user guide

58MCB
4-Way Multipoise
Fixed-Capacity
Condensing Gas Furnace
Service and Maintenance Instructions
For Sizes 040—140, Series 100
NOTE: Read the entire instruction manual before starting the
installation.
This symbol →indicates a change since the last issue.
ELECTRICAL SHOCK, FIRE, OR EXPLOSION
HAZARD
Failure to follow safety warnings exactly could result in
dangerous operation, serious injury, death, or property dam-
age.
Improper servicing could result in dangerous operation,
serious injury, death, or property damage.
- Before servicing, disconnect all electrical power to furnace.
- When servicing controls, label all wires prior to disconnect-
ing. Reconnect wires correctly.
- Verify proper operation after servicing.
ELECTRICAL SHOCK, FIRE OR EXPLOSION
HAZARD
Failure to follow this warning could result in possible damage
to this equipment, serious personal injury, or death.
The ability to properly perform maintenance on this equip-
ment requires certain expertise, mechanical skills, tools, and
equipment. If you do not possess these, do not attempt to
perform any maintenance on this equipment other than those
procedures recommended in the User’s Manual.
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could cause corrosion of heat
exchanger, fire, personal injury, or death.
Never store anything on, near, or in contact with the furnace,
such as:
1. Spray or aerosol cans, rags, brooms, dust mops, vacuum
cleaners, or other cleaning tools.
2. Soap powders, bleaches, waxes or other cleaning com-
pounds, plastic or plastic containers, gasoline, kerosene,
cigarette lighter fluid, dry cleaning fluids, or other volatile
fluids.
3. Paint thinners and other painting compounds, paper bags,
or other paper products.
TABLE OF CONTENTS
SAFETY CONSIDERATIONS.....................................................1
GENERAL......................................................................................2
ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS........2
CARE AND MAINTENANCE.....................................................3
Cleaning and/or Replacing Air Filter.......................................3
Blower Motor and Wheel Maintenance...................................3
Cleaning Burners ......................................................................5
Cleaning Heat Exchangers........................................................6
Primary Heat Exchangers ......................................................6
Secondary Heat Exchangers ..................................................8
Flushing Collector Box and Drainage System ........................8
Servicing Hot Surface Igniter...................................................9
Electrical Controls and Wiring.................................................9
Checking Heat Tape Operation (If Applicable) ....................10
Winterizing..............................................................................10
WIRING DIAGRAM...................................................................11
TROUBLESHOOTING ...............................................................11
Status Codes............................................................................11
Component Tests ....................................................................12
SAFETY CONSIDERATIONS
Recognize safety information. This is the safety-alert symbol .
When you see this symbol on the furnace and in instructions or
manuals, be alert to the potential for personal injury.
Understand the signal words DANGER, WARNING, CAUTION,
and NOTE. These words are used with the safety-alert symbol.
DANGER 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 may 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.
A93040
Visit www.carrier.com
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 4
Tab 6a 8a PC 101 Printed in U.S.A. Catalog No. 58MCB-1SM Pg 1 8-05 Replaces: 58MCA-10SM

Installing and servicing heating equipment can be hazardous due to
gas and electrical components. Only trained and qualified
service agency personnel should install, repair, or service
heating equipment. Untrained personnel can perform basic
maintenance functions described in User’s Information
Manual such as cleaning and replacing air filters. All other
operations must be performed by trained and qualified service
agency 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 including the National Fuel Gas Code
(NFGC) NFPA 54-2002/ANSI Z223.1-2002 in the U.S.A.; Na-
tional Standard of Canada, Natural Gas and Propane Installation
Code CSA B149.1-05 (NSCNGPIC) in Canada; and the Installa-
tion Standards, Warm Air Heating and Air Conditioning Systems
(NFPA 90B) ANSI/NFPA 90B. Wear safety glasses and work
gloves. Have a fire extinguisher available during start-up and
adjustment procedures and service calls.
ELECTRICAL SHOCK AND UNIT DAMAGE
HAZARD
Failure to follow this caution may result in minor personal
injury or damage to furnace.
Label all wires prior to disconnection when servicing con-
trols. Wiring errors can cause improper and dangerous
operation.
GENERAL
This furnace can be installed as a direct vent (2-pipe) or
non-direct vent (1-pipe) condensing gas furnace. These in-
structions are written as if the furnace is installed in an upflow
application. An upflow furnace application is where the blower is
located below the combustion and controls section of the furnace,
and conditioned air is discharged upward. Since this furnace can be
installed in any of the 4 positions shown in Fig. 2, you may need
to revise your orientation to component location accordingly.
ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS
UNIT DAMAGE HAZARD
Failure to follow this caution may damage furnace compo-
nents.
Electrostatic discharge can affect electronic components.
Take precautions during furnace installation and servicing to
protect the furnace electronic control. Precautions will pre-
vent electrostatic discharges from personnel and hand tools
which are held during the procedure. These precautions will
help to avoid exposing the control to electrostatic discharge
by putting the furnace, the control, and the person at the same
electrostatic potential.
1. Disconnect all power to the furnace. DO NOT TOUCH THE
CONTROL OR ANY WIRE CONNECTED TO THE CON-
TROL PRIOR TO DISCHARGING YOUR BODY’S ELEC-
TROSTATIC CHARGE TO GROUND.
2. Firmly touch a clean, unpainted, metal surface of the furnace
chassis which is close to the control. Tools held in a person’s
hand during grounding will be satisfactorily discharged.
3. After touching the chassis, you may proceed to service the
control or connecting wires as long as you do nothing that
recharges your body with static electricity (for example; DO
Fig. 1—Multipoise Furnace in Upflow Orientation
A05078
Fig. 2—Multipoise Orientations
A93041
UPFLOW
DOWNFLOW
HORIZONTAL
LEFT
AIRFLOW AIRFLOW
AIRFLOW
AIRFLOW
HORIZONTAL
RIGHT
2
→
→
→

NOT move or shuffle your feet, DO NOT touch ungrounded
objects, etc.).
4. If you touch ungrounded objects (recharge your body with
static electricity), firmly touch furnace again before touching
control or wires.
5. Use this procedure for installed and uninstalled (ungrounded)
furnaces.
6. Before removing a new control from its container, discharge
your body’s electrostatic charge to ground to protect the
control from damage. If the control is to be installed in a
furnace, follow items 1 through 5 before bringing the control
or yourself into contact with the furnace. Put all used AND
new controls into containers before touching ungrounded
objects.
7. An ESD service kit (available from commercial sources) may
also be used to prevent ESD damage.
CARE AND MAINTENANCE
For continuing high performance and to minimize possible furnace
failure, it is essential that maintenance be performed annually on
this equipment. Consult your local dealer about proper mainte-
nance and maintenance contract availability.
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury
or death.
Turn off the gas and electrical supplies to the unit before
performing any maintenance or service. Follow the operating
instructions on the label attached to the furnace.
The minimum maintenance that should be performed on this
equipment is as follows:
1. Check and clean or replace air filter each month as needed.
2. Check blower motor and wheel for cleanliness annually.
3. Check electrical connections for tightness and controls for
proper operation each heating season. Service as necessary.
4. Check for proper condensate drainage. Clean as necessary.
5. Check for blockages in combustion-air and vent pipes annu-
ally.
6. Check burners for cleanliness annually.
CUT HAZARD
Failure to follow this caution may result in personal injury.
Be careful of sharp metal edges, etc. Use care and wear
protective clothing, safety glasses, and gloves when removing
parts.
Step 1—Cleaning and/or Replacing Air Filter
The air filter arrangement may vary depending on the application
or orientation.
FIRE, CARBON MONOXIDE AND POISONING
HAZARD
Failure to follow this warning could result in fire, personal
injury, or death.
Never operate unit without a filter or with the blower access
panel removed. Operating a unit without a filter or with the
blower access door removed could cause damage to the
furnace blower motor. Dust and lint on internal parts of
furnace can cause a loss of efficiency.
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.
To clean or replace the filters, proceed as follows:
1. Turn off electrical supply to furnace.
2. Remove main furnace door and blower access panel.
3. Release filter retainer wire. (See Fig. 3 or 4.)
4. Slide filter out of furnace.
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.
7. Slide filter into furnace.
8. Recapture filter retainer wire.
9. Replace blower access panel and main furnace door.
10. Turn on electrical supply to furnace.
Step 2—Blower Motor and Wheel Maintenance
To ensure long life, economy, and high efficiency, clean accumu-
lated dirt and grease from blower wheel and motor annually.
WASHABLE
FILTER
FILTER
SUPPORT FILTER
RETAINER
A93046
Fig. 3—Bottom Filter Arrangement
FILTER
RETAINER
WASHABLE
FILTER
A93045
Fig. 4—Filter Installed for Side Inlet
3

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.
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 blower motor wires from furnace control. Field
thermostat connections may need to be disconnected depend-
ing on their length and routing.
4. Remove control box mounting screws, and 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. (See Fig. 5.)
a. Disconnect field drain connection from condensate trap.
b. Disconnect drain and relief port tubes from condensate
trap.
c. Remove condensate trap from blower shelf.
6. Remove screws securing blower assembly to blower shelf and
slide blower assembly out of furnace. Detach ground wire and
disconnect blower motor harness plugs from blower motor.
NOTE: Blower wheel is fragile. Use care.
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.
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:
a. Mark blower wheel location on shaft before disassembly to
ensure proper reassembly.
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.
c. Mark blower wheel orientation and cutoff plate location to
ensure proper reassembly.
d. Remove screws securing cutoff plate and remove cutoff
plate from housing.
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. Motor mounts need not be removed from
motor.
f. Remove blower wheel from housing.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in noise or furnace
component failure.
The blower wheel should not be dropped or bent as balance
will be affected.
g. Clean wheel per instructions on degreaser cleaner. Do not
get degreaser cleaner in motor.
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. Tighten setscrew to 140 to 160
in-lb torque.
NOTE: Be sure to attach ground wire and reconnect blower
harness plugs to blower motor.
10. Reinstall blower assembly in furnace.
11. Reinstall control box, transformer, and door switch assembly
on blower shelf.
12. Reinstall condensate trap and tubing if previously removed.
a. Reinstall condensate trap in hole in blower shelf.
b. Connect condensate trap drain tubes. See Fig. 10 or tubing
diagram on main furnace door for proper tube location.
NOTE: Ensure tubes are not kinked or pinched, as this will affect
operation.
(1.) Connect 1 tube (blue or blue and white striped) from
collector box.
(2.) Connect 1 tube (violet or unmarked) from inducer
housing.
(3.) Connect 1 tube (relief port, green or pink) from
collector box.
c. Connect field drain to condensate trap.
NOTE: Ensure tubes are not kinked or pinched, as this will affect
operation.
Fig. 5—Factory-Shipped Upflow Tube
Configuration
(Shown with Blower Access Panel Removed)
A01030
COLLECTOR BOX
TUBE (PINK)
COLLECTOR BOX
TUBE (GREEN)
INDUCER HOUSING
(MOLDED) DRAIN
TUBE (BEHIND
COLLECTOR BOX
DRAIN TUBE)
COLLECTOR BOX
DRAIN TUBE (BLUE)
FIELD-INSTALLED
FACTORY-SUPPLIED
DRAIN TUBE
COUPLING (LEFT
DRAIN OPTION)
FIELD-INSTALLED
FACTORY-SUPPLIED
DRAIN TUBE
FIELD-INSTALLED
FACTORY-SUPPLIED
1⁄2-IN. CPVC STREET
ELBOWS (2) FOR
LEFT DRAIN OPTION
FIELD-INSTALLED
FACTORY-SUPPLIED
DRAIN TUBE
COUPLING (RIGHT
DRAIN OPTION)
CAP
COLLECTOR BOX
DRAIN TUBE (BLUE
& WHITE STRIPED)
PLUG
CONDENSATE
TRAP
4
→
→
→
→
→

13. Reconnect wires.
Refer to furnace wiring diagram, and connect thermostat leads if
previously disconnected. (See Fig. 21.)
NOTE: Refer to Table 1 for motor speed lead reconnection if
leads were not identified before disconnection.
UNIT DAMAGE HAZARD
Failure to adjust the heating speed may shorten heat ex-
changer life.
Heating speed selection MUST be adjusted to provide proper
temperature rise as specified on the rating plate.
14. Turn on electrical supply. Manually close blower access door
switch. Use a piece of tape to hold switch closed. Check for
proper rotation and speed changes by performing a component
self-test as shown at the bottom of Service Label. (See Fig.
20.)
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury
or death.
Blower access door switch opens 115-v power to furnace
control. No component operation can occur. Caution must be
taken when manually closing this switch for service purposes.
15. If furnace is operating properly, remove tape to release blower
access door switch, replace blower access door, and replace
main furnace door.
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:
1. Turn off gas and electrical supplies to furnace.
2. Remove main furnace door.
3. Remove burner box cover.
4. Using backup wrench, disconnect gas supply pipe from
furnace gas control valve.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in furnace compo-
nent damage.
Label all wires prior to disconnection when servicing con-
trols. Wiring errors can cause improper and dangerous
operation.
5. Remove wires from gas valve. Note location for reassembly.
6. Remove burner box pressure tube from gas valve regulator
fitting.
7. Unplug igniter from harness.
8. Remove igniter leads from slot in manifold grommet.
9. Remove screws that secure manifold to burner box. (See Fig.
6.)
NOTE: Do not remove burner box from cell panel.
10. Remove manifold, orifices, and gas valve as one assembly.
11. Remove screws attaching burner assembly in burner box.
NOTE: Use care when removing and reinstalling burners not to
strike the hot surface igniter.
12. Remove burner assembly from burner box.
NOTE: All burners are attached to burner bracket and can be
removed as 1 assembly.
13. Clean burners with soft brush and vacuum.
14. Reinstall manifold, orifice, and gas valve assembly in burner
box. Ensure manifold seal grommet is installed properly and
burners fit over orifices.
15. Reinsert the igniter wires in the slot in the manifold grommet,
dressing the wires to ensure there is no tension on the igniter
itself. (See Fig. 7.)
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in electrical shock,
personal injury, or death.
Igniter wires must be securely placed in slot in manifold
grommet or else they could become pinched or severed and
electrically shorted.
16. Reconnect wires to gas valve and igniter. Refer to furnace
wiring diagram for proper wire location.
17. Reinstall burner box pressure tube to gas valve regulator
fitting.
18. Reinstall gas supply pipe to furnace gas control valve using
backup wrench on gas valve to prevent rotation and improper
orientation.
NOTE: Use propane gas resistant pipe dope to prevent gas leaks.
DO NOT use Teflon tape.
Table 1—Speed Selection
COLOR SPEED FACTORY
ATTACHED TO
Black High Cool
Yellow (When Present) Medium High Spare
Blue Medium Low Heat
Red Low Spare
White Common Com
Fig. 6—Burner Box Assembly
A96304
MANIFOLD
MOUNTING
SCREW
MANIFOLD
GAS VALVE
REGULATOR
FITTING
GAS VALVE
CELL
PANEL
5
→
→
→
→
→

FIRE, EXPLOSION, UNIT DAMAGE HAZARD
Failure to follow this warning could result in property
damage, personal injury, or death.
Gas valve switch MUST be facing forward or tilted upward.
19. Replace burner box cover.
20. Turn on gas and electrical supplies to furnace.
FIRE OR EXPLOSION HAZARD
Failure to follow the safety warnings exactly could result in
serious injury, death, or property damage.
Never test for gas leaks with an open flame. Use a commer-
cially available soap solution made specifically for the
detection of leaks to check all connections.
21. Check for gas leaks.
22. 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.
1. Turn off gas and electrical supplies to furnace.
2. Remove main furnace door.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in furnace compo-
nent damage.
Label all wires prior to disconnection when servicing con-
trols. Wiring errors can cause improper and dangerous
operation.
3. Disconnect wires or connectors to flame rollout switch, gas
valve, igniter, and flame sensor.
4. Disconnect combustion-air intake pipe from intake housing.
5. Remove the pressure switch tube from intake housing.
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.
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.
10. Remove screws attaching burner box to cell panel. (See Fig.
6.)
NOTE: Burner box, cover, manifold, gas valve, and burner
assembly should be removed as 1 assembly.
11. Clean heat exchanger openings with a vacuum and a soft
brush. (See Fig. 8.)
→Fig. 7—Igniter Wire Placement
A05074
IGNITER WIRES MUST
BE PLACED IN THIS SLOT
Fig. 8—Cleaning Inlet Openings of Primary Heat
Exchangers
A96305
PRIMARY HX
INLET OPENINGS
Fig. 9—Combustion-Air Intake Housing Gasket
Repair
A93087
PAM
RTV
6
→
→

NOTE: After cleaning, inspect the heat exchangers to ensure they
are free of all foreign objects that may restrict flow of combustion
products.
12. Reverse items 4 through 10 for reassembly.
UNIT MAY NOT OPERATE
Failure to attach this ground wire to an adequate casing
ground may cause the furnace control to lock out.
The ground wire from the gas valve MUST be attached to the
burner box attachment screw.
NOTE: Be sure burner box gasket is installed between burner box
and cell panel. (See Fig. 6.) If gasket is damaged, replace it.
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, halogenated
hydrocarbons nor aromatic content, to prevent inadequate sealing),
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. 9.)
13. Refer to furnace wiring diagram and reconnect wires to flame
rollout switch, gas valve, igniter, 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.
10.)
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
Fig. 10—Furnace Pressure and Drain Tubing Diagram
A00308
Furnace is shipped from factory in upflow configuration. Pressure tube and drain tube routing MUST match the diagrams below.
Tube location when used in DOWNFLOW application
Tube location when used on
HORIZONTAL - RIGHT application
PLUG
CAP
COLLECTOR BOX DRAIN TUBE
(BLUE & WHITE STRIPED)
COLLECTOR BOX TUBE
(PINK)
COLLECTOR BOX DRAIN TUBE
(BLUE)
INDUCER HOUSING DRAIN TUBE
(VIOLET)
COLLECTOR BOX TUBE
(PINK)
COLLECTOR BOX DRAIN
TUBE
(BLUE& WHITE STRIPED)
COLLECTOR BOX DRAIN TUBE
(BLUE)
INDUCER HOUSING (MOLDED) DRAIN TUBE
(BEHIND COLLECTOR BOX DRAIN TUBE)
FIELD-INSTALLED
FACTORY-SUPPLIED DRAIN TUBE
COUPLING (LEFT DRAIN OPTION)
FIELD-INSTALLED FACTORY-SUPPLIED
DRAIN TUBE
FIELD-INSTALLED
FACTORY-SUPPLIED 1/2-IN.
CPVC STREET ELBOWS (2)
FOR LEFT DRAIN OPTION
COLLECTOR BOX TUBE
(GREEN)
CONDENSATE TRAP
CAP
Condensate Trap; Factory Installed
in Blower Shelf
CONDENSATE TRAP
COLLECTOR BOX TUBE (GREEN)
Condensate Trap on LEFT
Side Optional
CAP PLUG
COLLECTOR BOX
DRAIN TUBE (BLUE)
PLUGGED END
COLLECTOR BOX DRAIN TUBE
(BLUE& WHITE STRIPED)
COLLECTOR BOX
TUBE (GREEN)
COLLECTOR BOX
TUBE (PINK)
COLLECTOR BOX
EXTENSION TUBE
CONDENSATE TRAP
INDUCER HOUSING DRAIN TUBE (VIOLET)
COLLECTOR BOX
EXTENSION TUBE
COLLECTOR BOX TUBE
(PINK)
COLLECTOR BOX DRAIN TUBE
(BLUE)
COLLECTOR BOX TUBE
(GREEN)
CONDENSATE TRAP
INDUCER HOUSING DRAIN
TUBE (VIOLET) COLLECTOR BOX EXTENSION TUBE
COLLECTOR BOX DRAIN
TUBE
(BLUE & WHITE STRIPED)
Condensate Trap on
RIGHT Side
COLLECTOR BOX
EXTENSION DRAIN TUBE
DRAIN TUBE COUPLING
GAS VALVE
DRAIN TUBES ROUTED IN
FRONT OF GAS VALVE
PLUG
CAP
COLLECTOR BOX DRAIN TUBE
(BLUE & WHITE STRIPED)
CONDENSATE TRAP
COLLECTOR BOX
EXTENSION TUBE
COLLECTOR BOX
TUBE (GREEN)
INDUCER HOUSING
DRAIN TUBE
(VIOLET)
COLLECTOR BOX TUBE (PINK)
RELOCATE TUBE BETWEEN BLOWER
SHELF AND INDUCER HOUSING FOR
040,060, AND 080 HEATING INPUT
FURNACES
CAP
PLUG
COLLECTOR BOX DRAIN TUBE
(BLUE) COLLECTOR BOX EXTENSION TUBE
COLLECTOR BOX TUBE (PINK)
COLLECTOR BOX
TUBE (GREEN)
COLLECTOR BOX DRAIN TUBE
(BLUE AND WHITE STRIPED) INDUCER HOUSING DRAIN TUBE (VIOLET)
CONDENSATE TRAP
Condensate Trap on
LEFT Side
COLLECTOR BOX
DRAIN TUBE (BLUE)
PLUG
Tube location when used in UPFLOW application
Tube location when used on
HORIZONTAL - LEFT application
CAP
PLUG
COLLECTOR BOX
EXTENSION TUBE
DRAIN TUBE
COUPLING
COLLECTOR BOX EXTENSION DRAIN TUBE
(Blower access panel removed)
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.
NOTE:
324999-201 REV. C
FIELD-INSTALLED
FACTORY-SUPPLIED
DRAIN TUBE COUPLING
(RIGHT DRAIN OPTION)
BURNER ENCLOSURE
PRESSURE REFERENCE
TUBE ASSEMBLY BURNER ENCLOSURE
PRESSURE REFERENCE
TUBE ASSEMBLY
BURNER ENCLOSURE PRESSURE
REFERENCE TUBE ASSEMBLY
BURNER ENCLOSURE
PRESSURE REFERENCE
TUBE ASSEMBLY
BURNER ENCLOSURE
PRESSURE REFERENCE
TUBE ASSEMBLY
BURNER ENCLOSURE PRESSURE
REFERENCE TUBE ASSEMBLY
TUBE ROUTING
AUXILIARY "J" BOX RELOCATED HERE
7
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burners. Burner flames should be clear blue, almost transpar-
ent. (See Fig. 11.)
FIRE OR EXPLOSION HAZARD
Failure to follow the safety warnings exactly could result in
serious injury, death, or property damage.
Never test for gas leaks with an open flame. Use a commer-
cially available soap solution made specifically for the
detection of leaks to check all connections.
17. Check for gas leaks.
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
1. Turn off gas and electrical supplies to furnace.
2. Remove main furnace door.
3. Disconnect inducer motor and pressure switch wires or
connectors.
4. Disconnect pressure switch tubes.
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. 10.)
NOTE: Ensure the drain tube disconnected from the inducer
housing is higher than the collector box opening or water will flow
out of tube.
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.
9. Inspect inside area of collector box for any pieces of foreign
materials and remove them if present.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in furnace compo-
nent damage.
Do not use wire brush or other sharp object to inspect or
dislodge materials in secondary heat exchangers as cutting the
secondary heat exchanger protective coating may occur.
Flush with water only.
10. Reassemble inducer assembly by reversing items 5-7. Tighten
the vent coupling clamp screw(s) to 15 in.-lb. of torque.
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, halogenated hydrocarbons nor
aromatic content, to prevent inadequate sealing), to inducer hous-
ing. (See Fig. 12.) Apply a small bead of G.E. RTV 162, G.E. RTV
6702, or Dow-Corning RTV 738 sealant to groove in collector
box.
11. Refer to furnace wiring diagram and reconnect wires to
inducer motor and pressure switch or connectors.
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. 10.)
13. Turn on gas and electrical supplies to furnace.
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.
FIRE OR EXPLOSION HAZARD
Failure to follow the safety warnings exactly could result in
serious injury, death, or property damage.
Never test for gas leaks with an open flame. Use a commer-
cially available soap solution made specifically for the
detection of leaks to check all connections. A fire or explo-
sion may result causing property damage, personal injury, or
loss of life.
15. Check for gas leaks.
Fig. 11—Burner Flame
A89020
;;
;;
BURNER FLAME
BURNER
MANIFOLD
Fig. 12—Gasket on Collector Box A93081
RTV
PAM
8
→
→
→

16. Replace main furnace door.
Step 6—Servicing Hot Surface Igniter
The igniter does NOT require annual inspection. Check igniter
resistance before removal.
1. Turn off gas and electrical supplies to furnace.
2. Remove main furnace door.
3. Disconnect igniter wire connection.
4. Check igniter resistance. Igniter resistance is affected by
temperature. Only check resistance when the igniter is at room
temperature.
a. Using an ohm meter, check resistance across both igniter
leads in connector.
b. Cold reading should be between 40 ohms and 70 ohms.
5. Remove igniter assembly.
BURN HAZARD
Failure to follow this caution may result in minor personal
injury.
Allow igniter to cool before removal. Normal operating
temperatures exceed 2000°F.
a. Remove burner box cover.
b. Remove igniter wires from slot in manifold grommet. (See
Fig. 7.)
c. Using a 1/4 in. driver, remove the single screw securing the
igniter bracket to the burner box bracket (See Fig. 13.) and
carefully withdraw the igniter and bracket assembly
through the front of the burner box without striking the
igniter on surrounding parts. Note that the igniter bracket
has a handle that extends to the front of the burner box to
aid in handling. (See Fig. 13.)
d. Inspect igniter for signs of damage or failure.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in premature failure
of the igniter.
The igniter is fragile. DO NOT allow it to hit the side of the
burner box parts while removing or replacing it.
e. If replacement is required, replace igniter on igniter bracket
and then install assembly to burner box to avoid damage to
the igniter.
6. To replace igniter and bracket assembly, reverse items 5a
through 5d.
7. Reconnect igniter wire connection, and insert the igniter wires
in the slot in the manifold grommet, dressing the igniter wires
to ensure there is no tension on the igniter itself (See Fig. 7).
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in electrical shock,
personal injury, or death.
Igniter wires must be securely placed in slot in manifold
grommet or else they could become pinched or severed and
electrically shorted.
8. Reinstall burner box cover.
9. Turn on gas and electrical supplies to furnace.
10. Verify igniter operation by initiating furnace control self-test
feature or by cycling thermostat.
11. Replace main furnace door.
Step 7—Electrical Controls and Wiring
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury
or death.
There may be more than 1 electrical supply to the furnace.
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. 15 for field wiring information
and to Fig. 21 for furnace wiring information.
NOTE: If the polarity is not correct or the furnace is not properly
grounded, the STATUS LED on the furnace control will flash
rapidly and prevent the furnace from operating. The control system
also requires an earth ground for proper operation of the furnace
control and flame sensor.
The 24-v circuit contains an automotive-type, 3-amp fuse located
on the control center. (See Fig. 16.) 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 (3-amp). The control LED will flash status code 24
when fuse needs to be replaced.
With power to the unit disconnected, check all electrical connec-
tions for tightness. Tighten all screws on electrical connections. If
→Fig. 13—Igniter Bracket
A05075
BRACKET
IGNITER
9/16˝
11/16˝
EXTENDED IGNITER
BRACKET HANDLE
IGNITER BRACKET
MOUNTING SCREW
→Fig. 14—Igniter
A04181
2-5/32˝
9
→
→
→
→
→
→
→
→
→
→

any smoky or burned connections are found, disassemble the
connection, clean all parts, strip wire, and reassemble properly and
securely.
Reconnect electrical supply to unit and observe unit through 1
complete operating cycle for proper operation.
Step 8—Checking Heat Tape Operation (If Applicable)
In applications where the ambient temperature around the furnace
is 32°F or lower, freeze protection measures are required. If heat
tape has been applied, check to ensure it will operate when low
temperatures are present.
UNIT AND PROPERTY DAMAGE HAZARD
Failure to follow this caution may result in furnace compo-
nent failures or water property damage.
Operating a unit without a filter or with the blower access
door removed could cause damage to the furnace blower
motor. Dust and lint on internal parts of furnace can cause a
loss of efficiency. If this furnace is to be operated in an
unconditioned space where the ambient temperatures may be
32°F or lower, freeze protection measures must be taken. (See
Fig. 17.) See CONDENSATE DRAIN PROTECTION sec-
tion of Installation, Start-Up, and Operating Instructions.
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:
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 the tape.
3. Check that heat tape power supply circuit is on.
Step 9—Winterizing
UNIT DAMAGE HAZARD
Failure to follow this caution may result in furnace compo-
nent damage.
Freezing condensate left in the furnace may damage the
furnace.
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 cap from unused drain tap on inducer
housing. (See Fig. 18.)
4. Connect field-supplied 1/2-in. I.D. tube to upper inducer
housing drain connection.
UNIT DAMAGE HAZARD
Failure of plastic components may occur.
Do not use ethylene glycol (Prestone II antifreeze/coolant or
equivalent automotive type).
5. Insert funnel in tube and pour up to one quart of antifreeze,
propylene glycol (RV, swimming pool antifreeze, or equiva-
lent) into funnel until it is visible at point where condensate
enters open drain. (See Fig. 19.)
6. Reconnect drain cap to inducer housing.
7. Replace main furnace door.
8. Propylene glycol need not be removed before restarting
furnace.
Fig. 15—Field Wiring
A02174
115-V FIELD-
SUPPLIED
DISCONNECT
AUXILIARY
J-BOX
24-V
TERMINAL
BLOCK
THREE-WIRE
HEATING-ONLY
FIVE WIRE
NOTE 1
NOTE 2 FIELD-SUPPLIED
DISCONNECT
CONDENSING
UNIT
TWO
WIRE
FURNACE
C
O
N
T
R
O
L
R
G
COM
WCR GY
GND
GND
FIELD 24-V WIRING
FIELD 115-, 208/230-, 460-V WIRING
FACTORY 24-V WIRING
FACTORY 115-V WIRING
208/230- OR
460-V
THREE
PHASE
208/230-V
SINGLE
PHASE
BLOWER DOOR SWITCH
WHT
BLK
WHT
BLK
NOTES: Connect Y-terminal in furnace as shown for proper blower operation.
Some thermostats require a "C" terminal connection as shown.
If any of the original wire, as supplied, must be replaced, use
same type or equivalent wire.
W
Y
GND
THERMOSTAT
TERMINALS
1.
2.
3.
10