User`s manual

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36
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VI. MAIN BURNERS
At the beginning of each heating season, inspect for deterio-
ration or blockage due to corrosion or other causes. Observe
the main burner flames and adjust if necessary.
VII. FLUE GAS PASSAGEWAYS
To inspect the flue collector box and upper areas of the heat
exchanger:
1. Remove the combustion blower wheel and motor
assembly according to directions in Combustion-Air
Blower section below.
2. Remove the flue cover to inspect the heat exchanger.
3. Clean all surfaces as required using a wire brush.
VIII. COMBUSTION-AIR BLOWER
Clean seasonally to assure proper airflow and heating effi-
ciency. Inspect blower wheel every fall and periodically dur-
ing heating season. For the first heating season, inspect
blower wheel bimonthly to determine proper cleaning
frequency.
To inspect blower wheel, shine a flashlight into draft hood
opening. If cleaning is required, remove motor and wheel as
follows:
1. Slide burner access panel out.
2. Remove the 6 screws that attach induced-draft motor
housing to vestibule plate (Fig. 58).
3. The blower wheel can be cleaned at this point. If
additional cleaning is required, continue with Steps 4
and 5.
4. To remove blower, remove 2 setscrews.
5. To remove motor, remove 4 screws that hold blower
housing to motor mounting plate. Remove the motor
cooling fan by removing one setscrew. Then remove
nuts that hold motor to mounting plate.
6. To reinstall, reverse the procedure outlined above.
IX. LIMIT SWITCH
Remove blower access panel (see Fig. 3). Limit switch is
located on the fan deck.
X. BURNER IGNITION
Unit is equipped with a direct-spark ignition, 100% lockout
system. Integrated Gas Unit Controller (IGC) is located in
the control box (Fig. 15). The IGC contains a self-diagnostic
LED (light-emitting diode). During service, refer to the label
on the control box cover or Table 18 for an explanation of
LED error code descriptions.
A single LED on the IGC provides a visual display of opera-
tional or sequential problems when the power supply is
uninterrupted. When a break in power occurs, the IGC
will be reset (resulting in a loss of fault history. The indoor
(evaporator) fan ON/OFF times will also be reset. The LED
error code can be observed through the viewport.
If lockout occurs, unit may be reset by interrupting the
power supply to unit for at least 5 seconds.
Tabl e 18 — LED Error Code Description*
LEGEND
LED —
Light-Emitting Diode
*A 3 second pause exists between LED error code flashes. If more
than one error code exists, all applicable codes will be displayed in
numerical sequence.
†Indicates a code that is not an error. The unit will continue to operate
when this code is displayed.
NOTE:
Refer to Tables 19-22 for additional troubleshooting information.
A. Removal and Replacement of Gas Train (See Fig. 58)
1. Shut off manual gas valve.
2. Shut off power to unit and tag disconnect.
3. Slide out burner compartment side panel.
4. Disconnect gas piping at unit gas valve.
5. Remove wires connected to gas valve. Mark each
wire.
6. Remove wires from ignitor and sensor.
7. Remove the two screws that attach the burner rack to
the vestibule plate.
8. Slide the burner tray out of the unit (Fig. 45).
9. To reinstall, reverse the procedure outlined above.
B. Cleaning and Adjustment
1. Remove burner rack from unit as described above.
2. Inspect burners and if dirty, remove burners from
rack.
3. Using a soft brush, clean burners and cross-over port
as required.
4. Adjust spark gap. See Fig. 59.
5. Reinstall burners on rack.
6. Reinstall burner rack as described above.
XI. REPLACEMENT PARTS
A complete list of replacement parts may be obtained from
your distributor upon request.
LED INDICATION ERROR CODE DESCRIPTION
ON
Normal Operation
OFF
Hardware Failure
1 Flash†
Evaporator Fan On/Off Delay Modified
2 Flashes
Limit Switch Fault
3 Flashes
Flame Sense Fault
4 Flashes
4 Consecutive Limit Switch Faults
5 Flashes
Ignition Lockout Fault
6 Flashes
Induced-Draft Motor Fault
7 Flashes
Rollout Switch Fault
8 Flashes
Internal Control Fault
CAUTION: When servicing gas train, do not hit or
plug orifice spuds.