Allied A97USMV Installation Instructions Manual Download

Page: 65 / 78

506887-01

Page 65 of 78

Issue 1213

18. 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.

19. Back wash heat exchanger with soapy water solution or

steam. If steam is used it must be below 275°F (135°C).

20. Thoroughly rinse and drain the heat exchanger. Soap

solutions can be corrosive. Take care to rinse entire
assembly.

21. 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.

22. Re-secure the supporting screws along the vestibule

sides and bottom to the cabinet.

23. Reinstall cabinet screws on front flange at blower deck.
24. Reinstall the primary limit on the vestibule panel.
25. Route heating component wiring through hole in blower

deck and reinsert strain relief bushing.

26. Reinstall electrical junction box.
27. Reinstall the combustion air inducer. Reconnect the 4

pin plug to the wire harness.

28. Reinstall pressure switches and reconnect pressure

switch wiring.

29. Carefully connect combustion air pressure switch hosing

from pressure switches to proper stubs on cold end
header collector box.

30. Reconnect condensate drain line to the cold end header

box.

31. Use securing screws to reinstall flue collar to the top

cap on the furnace. Reconnect exhaust piping and
exhaust drain tubing.

32. Replace flexible exhaust adapter on combustion air

inducer and flue collar. Secure using two existing hose
clamps.

33. Reinstall burner box assembly in vestibule area.
34. Reconnect flame roll-out switch wires.
35. Reconnect sensor wire and reconnect 2 pin plug from

ignitor.

36. Secure burner box assembly to vestibule panel using

four existing screws. Make sure burners line up in center
of burner ports.

37. Reinstall gas valve manifold assembly. Reconnect gas

supply line to gas valve.

38. Reinstall burner box cover.

39. Reconnect 2 pin plug to gas valve.
40. Replace the blower compartment access panel.
41. Refer to instruction on verifying gas and electrical

connections when re-establishing supplies.

42. 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.

43. Replace heating compartment access panel.

Cleaning the Burner Assembly

Turn off electrical and gas power supplies to furnace.
Remove upper and lower furnace access panels.

Disconnect the 2 pin plug from the gas valve.

Remove the burner box cover.

Disconnect the gas supply line from the gas valve.
Remove gas valve/manifold assembly.

Mark and disconnect sensor wire from the sensor.
Disconnect wires from flame rollout switches.

Remove four screws which secure burner box assembly
to vest panel. Remove burner box from the unit.

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.

Reinstall the burner box assembly using the existing four
screws. Make sure that the burners line up in the center
of the burner ports.

Reconnect the sensor wire and reconnect the 2 pin plug
to the ignitor wiring harness. Reconnect wires to flame
rollout switches.

10. Reinstall the gas valve manifold assembly. Reconnect

the gas supply line to the gas valve. Reinstall the burner
box cover.

11. Reconnect 2 pin plug 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.