3/16 in. / 4.7 mm
MOTOR & FAN ASSEMBLY
• Open the louvered access panel opposite the burner end of heater.
1. Disconnect the motor leads.
2. Remove the screws securing the motor mounting plate to the housing.
3. Pull the motor and fan assembly from the housing.
4. Loosen set screws on the fan wheel and pull the fan wheel from the motor shaft .
5. Remove the four nuts securing the motor to the mounting plate.
6. See Figure below for fan wheel spacing.
Motor Mount Plate
Fan Wheel
Motor
Clearance
AIR PRESSURE SWITCH
The air pressure switch is located on the cold air housing internal to the heater. It must work properly to allow
an ignition cycle. If the air pressure switch contacts are closed before the ignition control starts the fan motor, or
do not close on a call for heat aft er the fan motor starts, ignition will not occur.
To service:
-- Disconnect the 2 wires attached to the switch. Unhook the air pressure line attached to the - (NEG) port.
Remove the 2 screws holding the switch to the cold air housing
-- Reassemble by reversing above steps.
28
Negative
Port (-)
Air Pressure
Switch
