I have a Bryant forced air furnace (1980 ?)I just replaced the 3 wire pilot safety switch , as I was told thats what was wrong with it. It worked fine for about 2 1/2 days then it went back to what it did before. The pilot sparks, then it lights and I have a flame for about ten seconds. Then when it looks like it's supposed to go into the furnace for the burners , it goes out.then it lights, then it goes out,(reapeats but doesn't go any further). Is the gas valve the problem ? Any help is appreciated.It's getting kinda cold.
I don't know but doc would no but i don't think he stops by. I seen some other guy had a problem like that. Sorry can't help. I will say this if that forced air furnace is 25 years old...WOW. I thought forced air furnances usely didn't last that long. I have a hot water boiler.