It is an old water heater, but I took the door off and peeked inside and discovered there was no flame. Following the instructions on the tank, I re-lit the pilot, but as soon as I let go of the ...

They are also found on water heaters. When it fails, ... Defective thermocouple can prevent furnace or water heater from working: The Weekly Fix. Updated: Jan. 30, 2015, 5:12 p.m.