older Bryant furnace not staying lit

It's -38 here in northern Ohio! I have a older Bryant furnace (40 years old or so) I can get the pilot lit, then I turn on the gas valve to on, and turn on the power to the furnace, the furnace will light the burners but after a few seconds I hear a pop in the control valve and the gas is shut off and everything goes out including the pilot. Now I did have to have the control valve replaced a couple years ago, it has a dual valve standing pilot control valve in it. Hope someone has an idea .. THANKS!

 

Welcome to the forums.

Is that a millivolt system ? No 24vac transformer. Two wires to the thermostat ?

A weak pilot generator or a defective themocouple if it's not a millivolt system.

 

If you just leave the valve in the pilot position & release the button, will the pilot stay lit?

 

Yes pilot stays lit, turn the valve to on and it continues to stay lit. I then turn the power switch on the side of the furnace on and the burners all light, however after about 5 seconds? I hear the pop come from the control valve and all gas is shut off and everything goes out , however the fan keeps running.

I'm not sure what your talking about as far as millivolt system goes, i think I'm looking at the thermostat it says "cam-stat" on it and "fixed limit 190F . It has 3 wires coming from it. also the switch on the side looks like a big transformer of some kind about the size of a baseball.

thank you guys so much

 

Do the burners go out at virtually the same time the fan comes on?

 

don't think so, sometimes the fan doesn't come on yet when the burners light. I messed with it for a few hours tonight. Don't think fan has any effect on when the gas goes out though

 

This is somewhat of a long shot but maybe the pilot orifice is dirty or slightly clogged. I suggest you remove the pilot assembly, brush with a fine wire brush, & flush with solvent such as carb cleaner then blow it out well. Put it back together & give it a go.

 

Im staying at my moms but will give it a go first thing in the morning. I really appreciate the advice. I will post the results tomorrow.

 

Hey, was the thermocoupler. The flame wasn't hitting it directly enough so i adjusted it a little bit, seemed to do the trick. Thanks for the suggestions!

 

It may be that it was dirty which can affect operation. A new one is about $10-15 and you can clean the old one with an abrasive pad, like a green meanie. I don't think they recommend steel wool or sandpaper...not sure.

Glad you have heat. I knew there was a reason I moved away from Ohio and never looked back. -38F? Good grief!

 

yeah i picked one up today for 11 dollars, gonna switch it out when it warms up a little bit. This is the coldest i can ever remember around here. It's -3 right now with out windchill!

 

Please get that thing checked out. Just because it's running now doesn't mean it's safe - you might need a new furnace, not a thermocouple.

30-40% of the heat you're paying for is going right up the chimney whether it's safe or not.