Hello. My upstaris furnace stopped working, just blows cold air. I've shut the thermostat off and on and watched the diagnostic codes through window in the access cover. The progression of diagnostic codes goes:
Flashing fast - normal call for heat
2 flashes - external lockout (retries or recycles exceeded).
The unit is: TRANE XR80 model TUD060C936K1, serial # 2223JMY2G install date 11/27/02
Can anyone provide additional information on the "2 flashes". That is, more on what 2 flashes indicates?