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Maintenance
MOTOR: The motor is lubricated for life and needs no oiling.
FILTERS: Size is 20” x 20” x 1” (508 mm x 508 mm x 25 mm). Should be inspected and replaced when dirty. Ordinarily replacement
is required twice per heating season and, perhaps, a third time if continuous blower operation is used.
NOTE: The elements have an automatic reset thermal cut-out which is set to open at 100°F (38°C). If it opens, the elements will be
de-energized until the cut-out resets itself.
WARNING
Cut 240 V power supply before removing the front panel!
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Troubleshooting
The first step in identifying an operational problem is to
determine whether the fault is in the furnace or in the thermostat
and/or its connecting wiring.
1. If the furnace will not start:
Turn the thermostat to its highest setting. If 24V is present
between terminals C and W, the thermostat has closed, so
the fault is in the furnace.
Otherwise, the thermosat or its
connecting wiring is the problem.
2. If the furnace will not turn off:
Turn the thermostat to its lowest setting. If there is no more 24V
between terminals C and W and the furnace continues to run,
the thermostat has opened properly and the problem resides
in the furnace. Otherwise, the fault is in the thermostat or its
connecting wiring. After the fault area is isolated by use of the
thermostat, a check of the following components can be made
more efficiently:
Problem
Possible defective parts or components
1. The furnace will not turn on.
- Thermostat
- Circuit breaker or fuse is open
- Motor or capacitor
- SPEED SELECTOR switch (open contact)
- Electronic control
- Transformer
2. Motor runs continuously.
- Thermostat wires incorrectly attached to the furnace
3. Elements on, but motor does not run.
- Motor or capacitor
- SPEED SELECTOR switch (open contact)
- Electronic control
4. Motor going on and off in short cycles
- Heat anticipator in thermostat incorrectly set or may be defective
(or in too long cycles).
5. The thermostat must be set much higher (or lower) - The thermostat is not leveled or out of calibration
than the desired house temperature.
6. Not enough heat.
- Elements or relays
- HEAT ACTIVATION switch set in LOW position
- Safety limits opening because duct obstruction or dirty filters are restricting air flow
- Defective or incorrectly wired two-stage or outdoor thermostat
- Lack of enough cold air returns in house
7. Two-stage or outdoor thermostat not operating
- HEAT ACTIVATION switch not set in LOW position
properly.
8. Breaker on front panel trips.
- Overcurrent on heating element. Reset the breaker.
If problem persists, call an electrician
9. Thermal cut-out opens.
- Airflow is reduced because of blocked ductwork or very dirty filters
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