SET ROOM THERMOSTAT TO
HIGH STOP POSITION
Check voltage across fan high limit switch
terminals (56).
MODEL: EXT
FUNCTION: Air Delivery
PROBLEM: Fan(s) do not operate.
Before starting any procedures listed below, check room thermostat and circuit breaker settings.
Make sure there is appropriate line voltage between F1/F3 terminal block positions in the heater.
The room temperature cannot exceed 85 degrees when performing the following test procedures.
NOTE: For cross reference to number coded components, refer to the Exploded View Diagram.
Check room thermostat (23) for
possible miscalibration.
Check voltage across F2 & F3
terminal block positions (24).
Fan(s) Do Not
Operate
Fan(s) Operate
Voltage
Present
Remove the purple wires from
the room temperature control
thermostat (23) and jumper
them together.
No Voltage Present
Replace
thermostat (23).
Fans Run
Check unit wiring.
Fans Do
Not Run
Fix Unit Wiring.
Replace Circuit
Board (29).
Incorrect
Correct
Replace fan limit
switch (56).
Remove fan assembly
(47) and check voltage
to fan motor(s) (53).
Voltage Present
No Voltage
Present
Check units
internal wiring.
Check fan impeller for
debris that could cause
jamming. Replace if
necessary.
No Voltage
Present
Voltage
Present
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