To test your water heater thermocouple, use a digital multimeter set to the millivolt (mV) DC scale. Disconnect the thermocouple lead from the gas control valve, attach the multimeter's positive probe to the copper lead tip and the negative probe to the outer threaded brass body, and ignite the pilot light while holding the control button down. A healthy thermocouple exposed to an active pilot flame should generate between 20 to 30 millivolts. If the reading falls below 12 millivolts or drops rapidly upon releasing the button, the thermocouple is defective. Verification: Confirm stable millivolt generation exceeding 20 mV before concluding the thermocouple is functional.
1 votes
Marked as accepted