I have a Trane XR80 that's around 3-4 years old. I woke this morning and noticed a 6 degree difference between the thermostat setting and actual temp (set at 68, actual 62). Felt the vents, nothing.
I looked at the furnace and noticed the lights flashing twice (lockout). I cycled power twice within 30 seconds as suggested. The unit powered up. Steady flashing lights (call for heat) for about 60secs and then I heard what sounded like the igniters trying to work for about 3 seconds. The unit sounded like it powered down but I think the blower was still going. I checked the light and it was flashing 9 times (check igniter).
Next step is CALL A TECH i'm sure. Any idea what would cause this? It worked great yesterday. I noticed that the unit has a 20 year warranty on the heat exchanger and wondered if this fell under that. Any advice would be appreciated.