So I have had furnace man come out 4 times, plus the Gas company. Here is what has been done: - New thermocoupler - Two new gas valves - New Orface and line blown out - Gas company changed gas valve on outside of building.

Everytime I hear the "click" like the furnace is going to go on I listen for the burners to come on which is 99.9% of the time, never. It seems the thermostat is sending its signal to the furnace to start but with that "click" the pilot light goes out. Talked to two other furnace people and they have no clue either, other to say bad thermocoupler. WTH is wrong with this thing. Been good for years and just started this crap last November 2017.

  • 1
    This was happening on our gas-fired water heater a while ago. There was a small filter grille on the bottom of the unit that had become clogged with lint and other basement detritus. Every time the gas kicked on it became oxygen-starved and died. Blowing that out and vacuuming up any dust around the heater took care of it
    – Drew
    Commented Nov 13, 2018 at 19:34
  • Is the vacuum sensor on the forced air exhaust fan still good? The rubber ones degrade over a period of years, and can cause symptoms as you describe. Commented Feb 25, 2020 at 0:29

1 Answer 1


A good serviceman should be able to figure out what the problem is and how to correct it. Things to check; does the inlet gas pressure fall when the gas valve clicks, does the pilot go out instantly, is it blowing out or is the gas pressure to the pilot changing, did you keep the old gas valve for reference or throw it away? If you can, post a few pictures of the furnace and gas line connections at the furnace and state the furnace make and model and where you live.

  • Thank you for your answer. No sure how to add a picture of furnace, etc. It is a Peerless wall furnace, approx. 30+ years old from my uncles basement. Originally was gas, then converted to propane for our cabin and then back to gas by Gas Company approx. 1994. Pilot light has gone out immediately upon turning up or down the thermostat. Serviceman took old gas valve which I believe was a Honeywell 35,000 BTU. He put in a Robertshaw gas valve. Gas company adjusted pilot light on Oct. 4 when he put in a new orfice in the gas valve outside line. He said pressure was good to house.
    – user91810
    Commented Oct 9, 2018 at 2:43

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.