Thermocouple Testing

SERVICE PROCEDURE RG-V

Gas Valve

Testing and Replacement (White Rodgers/Robertshaw)

See SERVICE PROCEDURE RG-II

MAGNET ASSEMBLY TESTING (White Rodgers Control)

Step 1. Following the lighting instruction label on the heater, proceed to light the pilot and allow to operate for

three minuets. If the pilot will not stay lit, hold the pilot button (located on the gas valve) down during this test.

Step 2. Using a multimeter capable of measuring millivolts, connect one lead

using an alligator clip to the copper sheath of the thermocouple, use the second lead of the multi meter to probe the top terminal located at the back of the gas valve.

Probe top terminal on back of combination

thermostat/gas valve Alligator clip to copper sheath of thermocouple

Step 6. With a meter reading of 13 millivolts or greater, rotate knob of combination thermostat/gas valve to the “OFF” position.

Step 7. The magnet should remain closed for a drop of at least 6 millivolts. You will here a “snap” or “click” sound

when the magnet opens, if you hear this sound prior to a drop of 6 millivolts, the magnet is out of specification and the gas valve should be replaced.

MAGNET ASSEMBLY TESTING (Robertshaw Control)

Step 1. Disconnect thermocouple from gas valve.

Step 2. Connect a thermocouple adaptor (BWC P/N 239-44642-00, Robertshaw P/N 75036) at the

thermocouple location in the gas valve.

Step 3. Reconnect thermocouple to adaptor. Make certain all connections are tight (finger tight plus ¼ turn).

Step 4 Using a multimeter capable of measuring millivolts, connect one alligator clip to the set screw of the adaptor 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 minuets.

Step 6. With a meter reading of 13 millivolts or greater, rotate knob of gas valve to the “OFF” position.

Step 7. The magnet should remain closed for a drop of at least 6 millivolts. You will here a “snap” or “click” sound

when the magnet opens, if you hear this sound prior to a drop of 6 millivolts, the magnet is out of specification and the gas valve should be replaced.