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507389-02
Issue 1733
Maintenance
ELECTRICAL SHOCK, FIRE OR EXPLOSION
HAZARD
Failure to follow safety warnings exactly could result in
dangerous operation, Serious injury, death or property
damage.
Improper servicing could result in dangerous operation,
Serious injury, death or property damage
• Before servicing, disconnect all electrical power to
furnace
• When servicing controls, label all wires prior to
disconnecting reconnect wires correctly.
•
Any disassembly of components containing flue
or vent gases shall be done by a qualified service
agency.
• Verify proper operation after servicing.
WARNING
The HWC9 models are newly designed with improved
performance and added features over previous models.
Refer to Figure 10 for heating cabinet component layout. It
is recommended that the furnace be inspected annually by
a qualified service person.
Burner & Manifold Assembly
To remove the burner & manifold assembly:
1. Disconnect electrical service and turn off gas to the
appliance.
2. Loosen the pipe union external to the unit and remove
the gas line to the gas valve.
3.
Disconnect the orange high voltage spark wire at the
ignition control board.
4.
Disconnect the white flame sensor wire at the flame
sensor on the underside of the burner assembly.
5. Disconnect the orange and yellow wires at the rollout
switch.
6. Disconnect the red and blue wires at the gas valve.
7. Refer to Figure 11. Remove the two screws on the
burner assembly that secure it to the mounting
brackets. The mounting brackets contain pins to locate
the assembly and hold it in place after the screws are
removed. The mounting brackets are hidden until the
burner assembly is removed.
8. First, carefully pull the burner assembly toward you
until it is clear of the locating pins in the mounting
brackets.
9. Then move the assembly away from the vest panel.
10. Finally, pull the assembly from the unit.
11. Once the burner assembly is removed, the burners
can be cleaned using a bottle brush.
12. For reassembly, follow the above steps in reverse
order. Use caution to insure rear of manifold assembly
is properly engaged in rear mounting bracket.
Control Board Mounting Bracket
The control board mounting bracket can be removed to
allow component access for some service procedures.
The ignition control board and the inducer prover switch
are mounted to the bracket.
1. Disconnect electrical service and turn off gas to the
appliance.
2.
The bracket is secured with 2 screws visible at
the bottom of the bracket, below the ignition board.
Remove the screws. Additionally, a slot in the upper
left-hand edge of the control board bracket engages a
tab on a vest panel bracket.
3. With the wires and connectors in place, move the
board and bracket to the right to disengage the tab
from the slot to create access.
4. It may be necessary to remove the inducer prover
switch tubing at the switch.
5. For reassembly, follow the above steps in reverse
order.
Igniter
The igniter can be accessed from the front of the unit
without removing any other components. To remove the
igniter:
1. Disconnect electrical service and turn off gas to the
appliance.
2.
Disconnect the orange high voltage spark wire at the
ignition control board.
3. Remove the screw and pull the igniter out of the burner
assembly.
4. For reassembly, follow the above steps in reverse
order.
Rollout Switch
If for any reason the heat exchanger becomes blocked
the temperature-sensitive rollout switch located beside the
burners will open and the ignition control will turn off the
burners. After investigating and correcting the problem,
the rollout switch must be manually reset by pressing the
button on top of it.
The rollout switch can be accessed from the front of the
unit without removing any other components. To remove
the rollout switch:
1. Disconnect electrical service and turn off gas to the
appliance.
