I have an older gas furnace. The pilot light will not stay lit. I replaced the thermocouple and that did not work. Any suggestions? I am a rookie when it comes to furnaces and any feedback would greatly appreciated.
The pilot flame has to be clean and impinge on the thermocouple. It can't be a yellow lazy flame. You probably need to clean the pilot burner orifice with a tiny wire. Most thermocouples are replaced because the pilot isn't clean.
If you can light the pilot and the flame is hitting the top 1/3 of the thermo and it's a blue flame then when you release the pilot light it goes out you probably have a gas valve gone bad. You also could have overtightened the new themocouple. With a good multimeter you tell if the thermocouple is getting the required heat to activate the magnet. Still thinking valve though.