I'm having a problem with my Coleman Evcon furnace that I'm hoping someone might recognize.
Basically the furnace turns on and operates fine, but then after a short while will turn back off again. This happens quickly enough that the house never gets a chance to warm up to the set temperature. The thermostat is still calling for heat (there's a light) but the furnace ignores this and remains off.
Resetting any part of the system makes the furnace come back on immediately. What I mean is that if you pull the batteries on the thermostat and put them back in, up it goes. It also happens when the thermostat changes programs, from night to morning for instance, which I _believe_ cycles power on the control circuit. This also works if you cycle the power on the furnace itself.
I have a _feeling_ that the furnace control board is getting into some "state" that makes it ignore the fact that the heat signal is turned on. Resetting the electronics fixes the problem. But if this is the case, wouldn't the status light be trying to tell us this? Throughout everything the service light has remained a perfectly steady green.
I just pulled the filter and it definitely is a problem. But again, if this was the problem wouldn't there be some indication? Why would the furnace simply shut down?
Maur