Furnace is a TUY080R9V3V and is 11 years old. Beginning last year, it would not produce heat... no flame.
This year it is happening more often with a code of 2 flashes=EXTERNAL LOCKOUT (RETRIES OR RECYCLES EXCEEDED).
I am thinking the hot surface ignitor might be the culprit or the flame sensor?
This AM it took several tries to light the gas manifold, but it finally lit.
This afternoon it was blowing cold air again. I reset it by shutting it off 3 times within 30 seconds and then it started OK.
I am puzzled... and cold.
Thanks, Rich wbcci3371atGmaildotcom