Bobbo wrote:
wa8yxm wrote:
Though as someone said Thermocouples CAN go bad. Very rare
This statement I disagree with. In my vast experience, every time that a pilot light would not stay lit, it was the thermocouple that had gone bad. That probably amounts to 3 times in my 64 years.
my exerience. In my trailer WH or house WH haven't had a thermocouple go bad. But in my house gas fireplace I've had several fail and need replacing. Output voltage open circuit was fine, but with it attached to the load, voltage dropped well below the min voltage. New thermocouple, all good again..
The construction of a thermocouple is pretty simple and one would expect them to have a long life, and they are pretty reliable, but not 100%.
Often times they haven't failed, but the real cause is a poor pilot flame or a dirty thermocouple or connector. Check that before replacing one..