Open Circuit Thermocouple Testing

SERVICE PROCEDURE RG-II

Thermocouple Testing and Replacement

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

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 RG-I, steps 3a through 3c.

Step 4 Disconnect thermocouple from combination thermostat/gas valve (3/8" wrench). 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 RG-I, Step 4.

Thermocouple position

Step 7. Install right side inner door per

SERVICE PROCEDURE RG-I,

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.