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TROUBLESHOOTING
If the furnace fails to operate check the following:
• Is the thermostat operating properly?
• Are the blower compartment door(s) in place?
• Is the furnace disconnect closed?
• Has the circuit breaker tripped or the control board fuse
burned open?
• Is the gas turned on?
• Are any manual reset switches open?
• Is the fi lter dirty or plugged?
• Is the fl ame sensor coated? (Remove and clean with
steel wool.
(Do not use emery cloth or sandpaper!)
• Is there blockage in the condensate drain switch? Also
verify that there is no double trapping of condensate.
• Is the secondary heat exchanger free of debris and
clogs?
• Is evaporator coil clean and free of debris
(If applicable).
Cleaning of Burners
If the burners must be cleaned, follow steps 1-12. See
Figure 34 or 35 (page 46) for component location and
identifi cation.
1. Shut off gas supply to the furnace at the meter or at
a manual valve in the supply piping.
2. Turn off all power to the furnace and set the thermostat
to it’s lowest setting.
3. Remove the burner door from the furnace.
4. Turn the gas control switch to the OFF position.
5. Disconnect the wires from the gas valve, igniter, fl ame
sensor, and fl ame rollout switch.
6. Using two wrenches, separate the ground-joint union
in the gas supply piping at the furnace.
7. Remove the piping between the Gas Valve and the
ground-joint union. (If applicable).
8. Remove all screws securing the Manifold Assembly
to the Burner Box.
9. Carefully remove the burner assembly from the
furnace.
DO NOT DAMAGE THE IGNITER WHILE
REMOVING THE BURNER ASSEMBLY.
10. Inspect the burners for accumulated dust or debris.
If necessary carefully clean them with a soft wire
brush and a vacuum cleaner.
DO NOT DAMAGE THE
IGNITER WHILE CLEANING THE BURNER.
11. Replace all the parts in reverse order from which they
were removed.
12. Follow the lighting instructions found on the furnace
door to return the furnace to operation. Verify proper
operation after servicing.
Heat Exchanger and Burner Maintenance
The furnace should operate for many years without soot
buildup in the fl ue passageways, however, the fl ue, vent
system, and burners should be inspected and cleaned
(if required) by a qualifi ed service technician annually to
ensure continued safe operation. Pay attention to any
deterioration from corrosion or other sources.
Lubrication
The bearings in the blower motor and inducer blower used
in these furnaces are pre-lubricated and sealed by the
manufacturer. No further oiling of the bearings is required
for the life of the motor.
Vent System
Check the inlet pipe (if applicable) and outlet pipe to ensure
they are not blocked by debris. Any damaged section of vent
pipe must be replaced, and any obstruction or blockage
must be removed prior to operating the furnace.
WARNING:
Holes in the vent pipe or heat exchanger can
cause combustion products to enter the home.
Replace the vent pipe or heat exchanger if leaks
are found. Failure to prevent the circulation
of combustion products into the living space
can create potentially hazardous conditions
including carbon monoxide poisoning that
could result in personal injury or death.
• Are all the LED’s on the furnace control board constantly
ON? If not, refer to Table 7 (page 33) or the wiring diagram
(Figure 24, page 34) to determine fault condition.
IMPORTANT NOTE: The furnace will lock out after 5
failed attempts for ignition and will try again every
hour if the call for heat remains.
• If the Inducer Blower is operating, and items above
have been verifi ed, check the Blower Limit Switch and
reset if necessary. See Figure 34 or 35 (page 46) for
component location.
• If the furnace operates when the Blower Limit Switch is
reset, contact a qualifi ed service technician to identify
and repair the problem.
• If the furnace still doesn’t operate, check the Flame Roll-
out Switches (Figure 34 or 35) and reset if necessary.
• If the furnace operates when the Flame Rollout Switch
is reset, contact a qualifi ed service technician to identify
and repair the problem.