A.O. Smith 120 trough 500 STEP 6 PC BOARD MOTOR TEST, Service Switch, Motor Lead Terminals

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

STEP 6 PC BOARD MOTOR TEST

STEP 6. PC BOARD/MOTOR TEST. Check for 24 VAC between the two motor lead

terminals of the PC board. Disconnect the wires for this test.

IF THEN

24 VAC is not present: • Replace the board (AOS part # 6522)

and go to step 7. The board and relay

are one piece. Regardless of which

part is defective, both parts should be

changed.

Voltage is present: • This verifies that the motor is receiving

power but not closing the damper.

• Replace the motor (AOS part # 6521)

and go to step 7.

Note: The service switch may be used to bypass the damper, while waitingfor a replacement part.

WARNING - In the event of damper motor failure, verify that the damper is in the "open"

position before utilizing the service switch. (BTR Series 106/107 and some prior series –

changed from momentary push button to service switch).

Service SwitchMotor LeadTerminals