Thermocouple/Thermopile Testing - Bradford White DV Series Service Manual

DV Series
Closed Circuit Thermocouple Testing (White Rodgers Mechanical)
Step 1. Closed circuit testing is the preferred method for testing the thermocouple. 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 pilot button (located on the combination
thermostat/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 multimeter to probe
the top terminal located at the back of the combination thermostat/gas valve.
Step 3. If meter reads 10 millivolts or higher, the thermocouple is O.K.. If reading is below 10
millivolts, replace the thermocouple.
Open Circuit Thermocouple Testing (White Rodgers Mechanical)
Step 1. Disconnect the thermocouple from the 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.
Service Procedure II
Thermocouple/Thermopile
Testing and Replacement
Alligator clip to copper
sheath of thermocouple
15
15