The pilot won't stay lit on my furnace, when I release the button it just goes out. This started occurring after I did some gas plumbing and had to relight the pilot. I suspected the thermocouple and replaced it, but this didn't fix the problem. I've used this furnace for over 15 years without replacing the thermocouple. Can someone recommend the next best course of action to keep my pilot lit?
Some things to note:
- The new thermocouple is a cheap "universal" thermocouple that I purchased from Amazon and it doesn't seem to sit in place tight but I don't think it's moving.
- There seems to be a secondary thermocouple-type wire running alongside the thermocouple and pilot gas line, though I ensured the thermocouple is not in contact with anything else.
- While holding the pilot light button down I get a blue flame with a yellow tip that's over an inch in length. I've held the button down for over the recommended 60 seconds.
- The thermocouple is below the pilot light, but the flame is definitely touching it.
- The furnace is definitely over 30 years old and was likely installed in the 60's.
Best Answer
If their is a good flame on the thermocouple then it is a bad gas valve. Sometimes if the gas valve is just barely bad a hotter thermocouple will work for a short time but finding a hotter thermocouple is just hit and miss. I have seen people try 4 thermocouples and the fifth one worked then they claimed the other four were bad. The furnace of course stopped working a few months later after the thermocouple mellowed a little.