That number is XXXXX an ac coil. Can you get the model of the furnace?
where would that be located?
It would be in top section of furnace.
Does the flame light for 3 seconds and then go out?
model # XXXXX
and yes, it does light and then go out after 3 seconds
do you mind doing a small hands on project?
In front of the burner will be an ignitor on one side...and at opposite end a flame rod known as a flame sensor.
Clean this rod off with a steel wool.
Then try unit again and tell me result.
just a sec
Excellent....much better than a service call huh?
Thanks for your "hands on"