flame sensor, my electric igniter is working, I clean the flame sensor, but unit still kicks on for 5 seconds then flame goes out, what could be wrong
Do you have a meter and a schematic or parts list?
I'd be looking to see what the flame sensor output is doing and what else besides a "no flame" condition can shut off the gas valve and at what point in the startup sequence.
Could be many things preventing the firing of the burners. Flame sensor being one.
Do you have any blinking trouble codes on the control board?