Page 18 of 21
507389-01
Issue 1504
replacement, or to access the heat exchanger and flue tube
extension for cleaning. To remove the combustion inducer:
1. Remove the control board mounting bracket as described
previously.
2. Disconnect the inducer motor leads.
3. Disconnect the inducer prover switch tubing at the switch.
4. Disconnect the drain hose tubing at the collector box.
5. Loosen the hose clamp at the inducer elbow-flue tube joint
(the upper hose clamp).
6. Remove the three screws securing the inducer to the cold-
end header box. Loosen clip at upper mount.
7. Pull the combustion inducer and elbow away from the vest
panel to move it free of the mounting legs on the cold-end
header box, while pulling the inducer elbow free of the flue
tube extension.
8. Pull the inducer and elbow out of the compartment.
6. The flue tube extension can be cleaned if necessary. Leave it
in place; do not remove it from the unit.
7. If replacing the inducer with a new part, be sure the correct
inducer orifice is snapped in place.
8. For reassembly, follow the above steps in reverse order.
Combustion inducer orifice
The combustion inducer orifice meters the air flow needed for
proper combustion. Orifices are unique to each heating input,
and the correct one must always be used. The orifices are color-
coded as an aid. Refer to Table 3:
Refer to Figure 10 to remove the combustion inducer orifice:
1. The combustion orifice is held in place with snap-fits at the
inducer inlet and at the indicator tab at the inducer mounting
foot.
2. With the combustion inducer out of the unit, carefully pry
the round portion of the orifice from the inducer inlet.
3. Remove the indicator tab from the inducer mounting foot.
Model
Orifice color
HWC9N22
Blue
HWC9N33
Black
HWC9N44
Gray
HWC9N55
Brown
Table 3
4. For reassembly, follow the above steps in reverse order.
Furnace condensate drain
The condensate drain ensures proper evacuation of furnace
condensate from the collector box and inducer out of the cabinet.
If hoses are disconnected or if the drain is removed and replaced,
the drain must be primed as described in the procedure outlined
in the “Start-up” section. To remove the condensate drain:
1. Disconnect the upper and lower drain hoses at the condensate
drain.
2. Remove the two screws that secure the drain to the vest
panel.
3. For reassembly, follow the above steps in reverse order.
4. Prime the condensate drain as described in the procedure
outlined in the “Start-up” section.
Heat exchanger inspection
The heat exchanger should be inspected periodically and cleaned
if necessary. The assembly can be inspected in place, but cleaning
requires accessing both ends of the primary and secondary tubes,
which can only be accomplished by removing the heat exchanger
assembly from the furnace cabinet. To access the primary heat
exchanger tubes for inspection:
1. Remove the burner & manifold assembly as described
previously.
2. Remove the control board mounting bracket as described
previously.
3. Check the tubes for evidence of soot. If the tubes are clean,
reassembly is the reverse of the above procedure. If there
is noticeable soot, continue with the heat exchanger removal
procedure to remove and clean the heat exchanger.
Combustion
Inducer
Snap into
place
first (visible
after
reinstalled
in unit)
Inducer
Orifice
----Then
Snap into
place
Figure 10