Occasional loss of flame

[dwelsh3]

Hi,

I have a 1990 Coleman direct vent gas furnace model # 4084A656. Periodically, during the heating cycle, the flame will go out and the blower will shut down but the draft inducer will continue to run until I turn off the system at the thermostat and then turn back on to restart. This only happens occasionally, but obviously something is going bad and I would like your expert opinion on what would be the most likely causes of this condition. There never is a problem with the burner lighting and this usually happens in the middle of the night, so if the temp had dropped 5-6 degrees, therefore requiring the furnace to run for an extended time, I might have to reset several times until the set temp is reached.
Thank you for your time and hopefully you can give me some suggestions on what to do.

Don

[Robert]

Hi Don,

Problems with roof jack not allowing proper combustion air intake, intermittent short in an electrical component, down draft from wind, snow build up around roof jack, dirty burner, partially clogged burner orifice.


Those are most common and first things to check. If all proves to be ok, then a call out to a local hvac contractor may be best and save $$$$$ before it actually shuts down all together.



Thanks,
Robert