507052-05
Page 52 of 54
Issue 1922
16.
Remove screws along vestibule sides and bottom
which secure vestibule panel and heat exchanger
assembly to cabinet. Remove two screws from blower
rail which secure bottom heat exchanger flange.
Remove heat exchanger from furnace cabinet.
17. Back wash heat exchanger with soapy water solution
or steam. If steam is used it must be below 275°F
(135°C).
18. Thoroughly rinse and drain the heat exchanger. Soap
solutions can be corrosive. Take care to rinse entire
assembly.
19. Reinstall heat exchanger into cabinet making sure
that the clamshells of the heat exchanger assembly
are resting on the support located at the rear of the
cabinet. Remove the indoor blower to view this area
through the blower opening.
20. Resecure the supporting screws along the vestibule
sides and bottom to the cabinet. Reinstall blower and
mounting screws.
21. Reinstall cabinet screws on front flange at blower
deck.
22. Reinstall the primary limit on the vestibule panel.
23. Route heating component wiring through hole in
blower deck and reinsert strain relief bushing.
24. Reinstall electrical junction box.
25. Reinstall the combustion air inducer. Reconnect the
combustion air inducer to the wire harness.
26. Reinstall pressure switches and reconnect pressure
switch wiring.
27. Carefully connect combustion air pressure switch
hosing from pressure switches to proper stubs on cold
end header collector box.
28. Reinstall condensate trap.
29. Reconnect exhaust piping and exhaust drain tubing.
30. Reinstall burner box assembly in vestibule area.
31. Reconnect flame rollout switch wires.
32.
Reconnect sensor wire and reconnect 2-pin plug from
ignitor.
33. Secure burner box assembly to vestibule panel using
four existing screws. Make sure burners line up in
center of burner ports.
34. Reinstall gas valve manifold assembly. Reconnect gas
supply line to gas valve.
35. Reconnect wires to gas valve.
36. Replace the blower compartment access panel.
37.
Refer to instruction on verifying gas and electrical
connections when re-establishing supplies.
38. Follow lighting instructions to light and operate furnace
for 5 minutes to ensure that heat exchanger is clean
and dry and that furnace is operating properly.
39. Replace heating compartment access panel.
Cleaning the Burner Assembly
1. Turn off electrical and gas power supplies to furnace.
Remove upper and lower furnace access panels.
2. Disconnect from the gas valve.
3. Remove the burner box cover.
4. Disconnect the gas supply line from the gas valve.
Remove gas valve/manifold assembly.
5. Mark and disconnect sensor wire from the sensor.
Disconnect 2 pin plug from the ignitor at the burner
box.
6. Remove four screws which secure burner box
assembly to vest panel. Remove burner box from the
unit.
7. Use the soft brush attachment on a vacuum cleaner
to gently clean the face of the burners. Visually
inspect the inside of the burners and crossovers for
any blockage caused by foreign matter. Remove any
blockage.
8. Reconnect the sensor wire and reconnect the 2 pin
plug to the ignitor wiring harness.
9. Reinstall the burner box assembly using the existing
four screws. Make sure that the burners line up in the
center of the burner ports.
10. Reinstall the gas valve manifold assembly. Reconnect
the gas supply line to the gas valve. Reinstall the
burner box cover.
11. Reconnect wires to gas valve.
12. Replace the blower compartment access panel.
13.
Refer to instruction on verifying gas and electrical
connections when re-establishing supplies.
14. Follow lighting instructions to light and operate furnace
for 5 minutes to ensure that heat exchanger is clean
and dry and that furnace is operating properly.
15. Replace heating compartment access panel.