Resettable Thermal Switch Testing And Replacement; Ed-V; Ed-Vi - Bradford White ECO-DEFENDER U130T*FRN Service Manual

RESETTABLE THERMAL SWITCH CONTINUITY TESTING
Step 1. Remove outer jacket door.
Step 2. Disconnect white wire leads from resettable thermal switch.
Step 3. Using a multimeter capable of measuring continuity (Ohms),
place one probe of meter on one of the brass connection tabs of
the resettable thermal switch, and the remaining probe on the
other connection tab.
Step 4. If continuity is indicated, the switch is closed, allowing millivolt current to pass.
Step 5. If continuity is not indicated, the switch is open, possibly due to an over heating condition. The switch is
designed to open at predetermined temperatures. An open switch can be reset by depressing the red colored
button located at the center of the switch. The overheating condition must be determined prior to putting the
water heater back in service.
PROBABLE CAUSE FOR RESETTABLE THERMAL SWITCH ACTIVATION
PROBABLE CAUSE
Burner Failure
Weak switch or switch
out of calibration.
Flammable vapor incident
CORRECTIVE ACTION
1. Inspect burner per SERVICE PROCEDURE

ED-VI

2. Replace burner per SERVICE PROCEDURE
ED-VI
1. Replace resettable thermal switch
1. Replace water heater.
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SERVICE PROCEDURE ED-VII
Resettable Thermal Switch
Testing and Replacement
21