I recently had to replace my t-stat for the heating unit: Carrier 58PAV070. I removed and replaced the old one (make unknown) with the Honeywell CT31A 4-wire unit. I matched up all signals based on color codes and terminal lugs: W -> W R -> R Y -> Y G -> G this left a BLUE wire unaccounted for which I taped off. sadly I did this at the end of summer and, after weeks of tossing the t-stat around, I finally throw it out failing to consider the HEATING side of the story - now I have come to realize my heater no longer turns on. The error indicator on the unit is solid red (normal?). AC works fine, just no heat - no flame, nothing. any help on restoring the heat would be appreciated. I believe it comes down to the BLUE wire marked "C" which has no corresponding lug for model CT31A t-stat. * also- I failed to power down heater prior to removal of t-stat: live & learn. Thanks in advance.

I have a Rheem Classic 90 plus and the the furnace will sound like it is working...the small blower starts, the igniter clicks and then the main blower kicks in and runs for a few minutes and then turns off, but the burner never lights and it just blows cold air. There are 3 lights when I take the blower panel off. If I push the lever to activate the system(as if the panel were in place) the 2 green light come on...OK and PWR. The orange flame light is not on. What can I do? It worked earlier today and is getting cold.