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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 local distributors.
Blower Compartment
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 steps 1 - 12. See
Figures 19 and 20 (page 35) for component location.
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 its 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 burner assembly to
the furnace.
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 that they were
removed.
12. Follow the lighting instructions found on the furnace
door to return the furnace to operation. Verify proper
operation after servicing.
Cleaning Of Flue Passages
If the fl ue passages must be cleaned, follow the steps
below. See Figures 19 and 20 for component location.
1. Shut off the gas supply to the furnace at the meter or
at the manual valve in the gas supply piping.
2. Turn off all power to the furnace and set the thermostat
to the lowest temperature setting.
3. Remove the blower door from the furnace.
4. Turn the gas control switch to the OFF position.
CAUTION:
Label all wires prior to disconnection when
servicing controls. Wiring errors can cause
improper and dangerous operation.
5. Disconnect the wires from the gas valve, fl ame sensor,
inducer, fl ame roll-out switch, limit switch, pressure
switch and igniter.
6. Remove the silicone rubber tube from the inducer.
7. Using two wrenches, separate the ground-joint union
in the gas supply piping at the furnace.
8. Remove the piping between the gas valve and the
ground-joint union. (If applicable).
9. Remove all screws securing the burner assembly to
the furnace.
10. Carefully remove the burner assembly from the furnace.
DO NOT DAMAGE THE IGNITER WHILE REMOVING
THE BURNER ASSEMBLY.
11a. Remove all screws securing the inducer assembly
to the vent pipe running out of the furnace
(*SA upfl ow/horizontal models only).
11b. Remove all screws securing the combustion air tube
assembly to the vent pipe running out of the furnace.
(*SK downfl ow models only).
12. Remove all screws securing the inducer assembly
to the collector pan.
13a. Carefully remove the inducer assembly and combus-
tion tube assembly from the furnace.
DO NOT BREAK
THE SEALS AT EACH END OF THE COMBUSTION
AIR TUBE.
(*SK downfl ow models only).
13b. Carefully remove the inducer assembly from the
furnace (*SA upfl ow/horizontal models only).
14. Remove all screws securing the collector pan to the
furnace.
15. Remove the collector pan and gasket from the
furnace.
16. Attach a round wire brush to a length of high grade
stainless steel cable. Attach the other end of the
cable to a variable speed reversible drill. Slowly insert
and rotate the cable into the top portion of the heat
exchanger. Operate the drill alternating between
forward and reverse, working the cable in and out
several times to obtain suffi cient cleaning. Repeat
this sequence for each heat exchanger tube.
17. Remove all loosened debris from the heat exchanger
tubes using a vacuum cleaner.
18. Using a bright light, check the condition of the upper
and lower sections of the heat exchanger tubes.
19. Inspect the burners for accumulated dust or debris.
If burners must be cleaned, see Cleaning of
Burners.
