Okay, so I've got a gas furnace, maybe 10 yrs old. Went to turn on the heat for the first time this season and am encountering this problem; Pilot light is on and functioning apparently great, but the main burners will not light. It appears as if nothing is happening at all when I adjust the thermostat. I have pressed a switch that is labeled "in for manual, out for auto" inside the furnace itself and the furnace sounds as if it is going well, the fan (I think, excuse my ignorance) turns on and it sounds like the furnace is getting ready and the burners will light any second, but then they just don't. I have left it on like this for a length of about 15 minutes with nothing happening at all.

I have turned off power to the furnace completely a few times, removed the fuse and checked her out, seems fine. I'm stumped. Any ideas? The furnace was in a home we bought last summer and the manual is MIA, it is a Johnson Air-Ease and I can give model # if it would help.

Thanks!

Sounds like a bad thermocouple, that is the little rod that the pilot light heats. If it is bad (not sensing heat) it won't allow the main valve to open.