SERVICE PROCEDURE
Thermocouple/Thermopile Testing and
Replacement
OPEN CIRCUIT THERMOCOUPLE TESTING (White Rodgers/Robertshaw Gas Valve)
Step 1. Disconnect thermocouple from combination thermostat/gas valve.
Step 2. Using a multimeter capable of measuring millivolts, connect one alligator clip to the end ball or contact portion of the thermocouple, and the other alligator clip to copper portion of the thermocouple.
Step 3. Following the lighting instruction label on the heater, proceed to light the pilot and allow to operate for three minutes. It will be necessary to hold the pilot button down continuously throughout this test. A reading of 20 to 30 millivolts indicates good thermocouple output.
THERMOCOUPLE REPLACEMENT (White Rodgers/Robertshaw Gas Valve)
Step 1. Turn off gas supply to water heater. Rotate knob of combination thermostat/gas valve to “OFF” position.
For White Rodgers Control, depress knob slightly and rotate clockwise to the “OFF” position.
For Robertshaw Control, rotate knob clockwise to the “OFF” position.
Step 2. Remove outer jacket door.
Step 3. Remove right side of inner door per SERVICE PROCEDURE
Step 4 Disconnect thermocouple from combination thermostat/gas valve. Locate other end of thermocouple inside of combustion chamber and remove from pilot bracket. Pull firmly pulling away from the pilot assembly.
Step 5. Install new thermocouple into pilot bracket making certain the thermocouple is fully engaged into the pilot bracket. Position thermocouple against left side inner door flange at its original position. Connect other end of thermocouple to combination thermostat/gas valve (finger tight + ¼ turn).
Step 6. Inspect inner door gasket per
SERVICE PROCEDURE
Thermocouple position
Step 7. Install right side inner door per
SERVICE PROCEDURE
Step 10 through Step 13
Step 8. To resume operation follow the instructions located on the lighting instruction label or the lighting instructions located in the installation and operation manual.
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