If there is no flame it will not be the flame sensor...the sensor is located at the left side of the burner...the ignitor at the right...do you see any glow after the exhaust fan starts?
How about a code flashing from circuit board?
Ok... went up stairs to turn heat on and look for flashing code. Of course the heat, with flame, pops right on.
What would be behaving like this and is there anything I need to do to keep it on and good?
Do you have snow accumulation?
Are the pipes clear outside?
Thank you....I asked about snow but wind can create the same fault. There is a pressure switch that relies on airflow through the pipes and furnace....if this is interruputed it can fault the unit.
If it happens again look at the circuit board in bottom and write down the blinks.
Then return and let me know.