Can I fix my own furnace?
You likely have an induced draft furnace. There is a small blower next to the exhaust flue that assists the flow of combustion gases through the heat exchanger (not to be confused with the large blower that pushes air through your house.) There is a diaphragm pressure valve that senses the negative air pressure in the flue when the inducer blower is running. If it doesn’t detect the pressure of the blower it won’t turn on the gas because the it thinks the fan has failed or the flue is blocked. Usually what happens is that the port in the flue through which the air pressure is sensed becomes plugged. First turn off your furnace by flipping the AC switch at the furnace. Take off the upper front panel of your furnace. You should see something that looks similar to the picture here. See the small inducer blower motor on the left and the plastic tube leading to the pressure switch on the right. It is
JackFlash, Thanks so much! That’s a lot of great information. You guys are great. Seriously. If any of you want some chocolate chip cookies or something drop me a mail and I will be more than happy to make some and send them out! My furnace is STARTED! I don’t really understand how, however. I mean, I looked at the picture JackFlash provided, but my furnace is not configured in an identical manner and the things he pointed out were not user accessible without taking apart a lot of other things (to use the technical lingo). I mucked around inside and plugged and unplugged some things and found the draft reset switch and hit it and gave it one last chance reboot and it fired right up. What the fuck. Thanks again you guys. You’re so amazing. !
I got money on what they call the roll out / flame out switches . Mine did this once before – same thing you are seeing. There are these sensor type switches that detect if the flame comes out of the heater box (i.e. they are testing temperature). They get old over the years (they take some abuse – hot dry air blows over them constantly). Your manual may show where they are – but there is a reset button on top of them that you can press to reset the switch. Big caveat here – if those switches are tripping for a reason it is because the flame is making it outside of the box – very dangerous. You will find one where the heated air exits your furnace unit. Mine had gone bad – I had to remove the switch and just wire the two wires together – until I could get a new switch in the morning. Please be careful – if this above your skill level wait until tomorrow – you are dealing with dangerous things as I am sure you know.
