Fan Motor - A.O. Smith Water Heater 520 Direct Vent Indoor Service Manual

10-3. Fan motor

Unit Part #
Function
Failure events
Effects on the water
heater if fan motor fails
Error codes when the fan
motor fails
Diagnostic
Color/Number of wires
PWN turbo fan motor
#114 AOS Part #
To provide combustion air into the combustion chamber and to exhaust flue
gas.
1. Fan speed failure, causing abnormal sounds with or without combustion
during operation.
2. Unexpected activation caused by the connectors of the fan motor getting
wet.
3. Disconnects from the bottom of the combustion chamber
1. The water heater does not function properly
2. Failure to ignite or abnormal ignition
3. Unstable combustion conditions
101 111
1. Visual inspection: connection/breakage of wires or dust (causing electrical
shortage)
2. Voltage check: proper range of voltages shown below.
Red-Blue 110 to 160 VDC (Input)
Yellow-Blue 13 to 17 VDC (Input)
Orange-Blue 2.0 to 6.5 VDC (Input)
Verify the fan motor speed using the Diagnostics Mode of
White-Blue
the 520 models computer board or the 9007603005
temperature remote controller. See Section 12-1 for details.
520 Indoor / 520 Outdoor Service Manual
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CONFIDENTIAL
Ver. 1.00
Checkpoint G1
611 991