After the furnace heats to the desired setting of the thermostat the gas flow to the burner stops and starts every few seconds with the igniter also starting and stopping. Igniter is 2yrs. old and won't last long operating like this.

kp2171

mine cycled on and off but at the beginning of the program... that is, the thermostat would tell the furnace to kick on, itd ignite, then within 10 secs the valve would shut down, and the cycle would start over again. cleaning the flame sensor fixed my problem, at least so far... furnace didnt sense that the flame was present when it was and it kicked the gas off and tried again...

but you are saying that itll follow the program until it hits the desired temp and then it just cycles on and off?

Todrick

I cleaned the flame sensor and seems to be working fine. Thanks for the help.

labman

Hummmmmmmmmmm! A lot of that around. I have a 12 year old Bryant 80+. I wonder if I should go ahead and clean it before cold weather sets in, or leave well enough alone? If it ain't broke, don't fix it?

kp2171

aint that the truth.. learned that the hard way a few years back... cleaning all the grime and gunk out when doing some home plumbing... thought, "well while i have the drain unattached i might as well clean some of the other junctions that look gunky"... and of course the gunk was the thing keeping half of them from leaking in the first place.

honestly, i didnt even take my flame sensor out of the furnace. shut power down, had reasonable access to reach in with a light sandpaper and just gave it a few strokes all around. went from having the occasional "why is it so darn cold" in the mornings when the furnace was told to kick in to now having no problems so far... hoping that little productive minute spent cleaning it gets me through the winter.

letmetellu

You must have a flame sensor or you would not say anything about cleaning it but that age is about the time that flame sensors started to being used. I would like to know if you do have a flame sensor.