581B,C
Step 11 —Combustion-Air Blower
Clean periodically to ensure proper airflow and heating efficiency. Inspect blower wheel every fall and periodically during heating season. For the first heating season, inspect blower wheel bimonthly to determine proper cleaning frequency.
To inspect blower wheel, remove draft hood and screen. Shine a flashlight into opening to inspect wheel. If cleaning is required, remove motor and wheel as follows:
1.Slide burner access panel out.
2.Remove the 5 screws that attach
3.Slide the motor and blower wheel assembly out of the blower housing. The blower wheel can be cleaned at this point. If additional cleaning is required, continue with Steps 4 and 5.
4. To remove blower from the motor shaft, remove
2setscrews.
5.To remove motor, remove the 4 screws that hold the motor to 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.
Step 12 —Limit Switch
Remove blower access panel (Fig. 8). Limit switch is located on the fan deck.
Step 13 —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. 13). A single LED on the IGC provides a visual display of operational or sequential problems when the power supply is uninterrupted. The LED can be observed through the viewport. When a break in power occurs, the IGC will be reset (resulting in a loss of fault history) and the evaporator fan on/off times delay will be reset. During servicing, refer to the label on the control box cover or Table 39 for an explanation of LED error code descriptions.
If lockout occurs, unit may be reset by interrupting power supply to unit for at least 5 seconds.
Table 38—LED Error Code Description*
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 | |
7 Flashes | Rollout Switch Fault |
8 Flashes | Internal Control Fault |
9 Flashes | Software Lockout |
LEGEND
LED —
*A
†Indicates a code that is not an error. The unit will continue to operate when this code is displayed.
IMPORTANT: Refer to Troubleshooting Tables for additional information.
Step 14 —Main Burners
At the beginning of each heating season, inspect for deterioration or blockage due to corrosion or other causes. Observe the main burner flames and adjust, if necessary.
!CAUTION
FURNACE DAMAGE HAZARD
Failure to follow this caution may result in reduced furnace life.
When servicing gas train, do not hit or plug orifice spuds.
Removal and Replacement of Gas Train
(See Fig. 63 and 64)
1.Shut off manual gas valve.
2.Shut off power to unit, tag disconnect.
3.Remove compressor access panel.
4.Slide out burner compartment side panel.
5.Disconnect gas piping at unit gas valve.
6.Remove wires connected to gas valve. Mark each wire.
7.Remove
8.Remove the 2 screws that attach the burner rack to the vestibule plate.
9.Remove the gas valve bracket.
10.Slide the burner tray out of the unit (Fig. 64).
11.To reinstall, reverse the procedure outlined above.
12.Reinstall burners on rack.
INDUCED- | ROLLOUT |
DRAFT | SWITCH |
MOTOR |
|
MOUNTING |
|
PLATE |
|
BURNER |
|
SECTION | FLUE |
| EXHAUST |
| VESTIBULE |
INDUCED- | PLATE |
DRAFT | BLOWER |
MOTOR | |
| HOUSING |
MANIFOLD | GAS |
PRESSURE | |
TAP | VALVE |
| C06152 |
Fig. 63 --- Burner Section Details
C06153
Fig. 64 --- Burner Tray Details
52
