Gas Furnace/no heat

My gas furnace works, everything kicks on, but right before the blower kicks on the gas stops...so basically it's blowing cold air. It just keeps doing this over and over and everyonce in a while the gas keeps burning and heat actually comes out, but not very often. Anyone know what might cause this? Thanks

Hi bflan, welcome to the forum Could you please specify which furnace you have/

I have a Tappan. I looked further and see a blinking yellow light which says I have "low flame sensor signal".....I found the flame sensor, is this something that I can purchase myself or do I have to be a contractor?? Thanks

Bflan perhaps your supply and exhaust lines are blocked orr have some kind of obstruction in them? (the latter being more realistic since the flow does seem to work until you turn on the blower)


You may also want to check the whole vent system, because I just now saw that this has restrictor plates behind them and this might be part of the problem?

Post edited by: Jeffie, at: 2008/01/19 08:27

Sounds to me like you have a problem with your high limit switch. If the high limit switch dosent detect enough heat it acts as a safety mechanism and shuts off the gas so you dont leak gas into the surrounding area.