Originally Posted By: Dave Sherman
Do you have a glow plug ignitor near the burner that lights up? I thought these were more common than spark ignitors, but I could be wrong. They can burn out.
Called a "hot surface igniter" and is the most common type. Mine went out a couple of years ago and I replaced it myself for $20. The furnace pictured is what we at work call a 90% furnace, meaning 90% efficiency. One PVC tube is the air intake from which the inducer motor draws combustion air. The other is exhaust. With a secondary heat exchanger the exhaust ends up being just warm rather than hot. My 1996 vintage 80% Bryant furnace has a blinking LED that indicates which circuit is at issue. I'd almost best it's your igniter. When it goes you get the gas turned on, which you can hear. After a few seconds, if the flame sensor doesn't detect heat, the gas valve shuts off the gas supply and the control board goes into error mode. As JC mentioned, the Honeywell Glowfly is a "universal" igniter made of silicon nitride. My Honeywell rep claims they are the most durable.