• Always reinstall the doors on the furnace after servicing
or cleaning/changing the ﬁ lters. Do not operate the
furnace without all doors and covers in place.
• Verify that the thermostat is properly installed and
is not affected by drafts or heat from lamps or other
• To achieve the best performance and minimize
equipment failure it is recommended that a yearly
maintenance checkup be performed. At a minimum,
this check should include the following items:
Never operate the furnace without a ﬁ lter in
place. Dust and lint in the return air can build
up on internal components, resulting in loss of
efﬁ ciency, equipment damage, and possible ﬁ re.
Note: Air ﬁ lter(s) are not supplied with the furnace as
shipped from the factory. The installer must provide a
high velocity ﬁ lter and rack for a ﬁ lter in the return air
duct adjacent to the furnace, or in a return air grill to the
furnace. It is recommended that ﬁ lters be 1" or 2" thick and
be cleaned or replaced monthly. New or newly renovated
homes may require more frequent changing until the
construction dust has minimized.
Filters designed to remove smaller particles such as pollen,
may require additional maintenance. Filters for side return
and bottom return applications are available from most
Dirt and lint can create excessive loads on the motor
resulting in higher than normal operating temperatures
and shortened service life. It is recommended that the
blower compartment be cleaned of dirt or lint that may
have accumulated in the compartment or on the blower
and motor as part of the annual inspection.
Cleaning of Burners
If the burners must be cleaned, follow the steps below and
see Figure 40 (page 51) for component location.
1. Shut off gas supply to the furnace either 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.
To prevent damage to the unit or internal
components, it is recommended that two
wrenches be used when loosening or tightening
nuts. Do not over tighten!
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
12. Follow the lighting instructions found on the furnace
door to return the furnace to operation. Verify proper
operation after servicing.
Heat Exchanger & 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.
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.
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.
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.