I have a Bryant furnace model 394GAZ036100. The problem I am having is intermitant. Furnace will run fine sometimes 6-8 hr, cycles OK and then doesn't start up on calling for heat. If I shut of power and turn it back on it will start and cycle OK. Never has messed up while I am sitting there watching it, LOL. Lights pilot OK, if I blow out pilot, lights it right back up, starts main burner and cycles through.

Clean the flame senser just for a start. Intermittant problems are a pain, even for a trained onsight pro, let alone us trying to help over the net.