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SERVICE PROCEDURE RG-II

Thermocouple Testing and Replacement

Closed Circuit Thermocouple Testing
Step 1. Disconnect thermocouple from combination thermostat/gas valve.
Step 2. Connect a thermocouple adapter (BWC P/N 239-44642-00,
Robertshaw P/N 75036) at the thermocouple location in the
combination thermostat/gas valve.
Step 3. Reconnect thermocouple to adapter. make certain all connections
are tight (finger tight plus 1/4 turn)
Step 4. Using a multimeter capable of measuring millivolts, connect one
alligator clip to the set screw of the adapter, and the other alligator
clip to copper portion of the thermocouple.
Step 5. Following the lighting instruction label on the heater, proceed to
light the pilot and allow to operate for three minutes. If the pilot
will not stay lit, hold the red reset button (located on the
combination thermostat/gas valve) down during this test.
Step 6. If meter reads 13 millivolts or higher, the thermocouple is OK. If reading is below13 millivolts replace
the thermocouple.
Open Circuit Thermocouple Testing
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 red reset button continuously
throughout this test. If meter reads 20 millivolts or higher, the thermocouple is OK. If reading is
below20 millivolts, replace the thermocouple.