said by KrK: said by TheMG: said by KrK:
Yeah I'd suspect your Flame sensor too. It's maybe dirty, or failed.
He did say that the burner actually ignites and stays on though, and then kicks out 3 seconds after the main blower comes on.
The way I read it the blower comes on, the igniter ignites the gas, and three seconds later the gas shuts down, killing the burners, and then the blower finishes the cycle.
That's exactly what mine does if the flame sensor is disconnected. The guy checked the safety on the inspection by firing it up with the flame sensor d/c'ed. The thing fires, the flame sensor doesn't detect it, safety kicks in and shuts off gas.
Pretty much exactly what happens when our flame sensor needs to be cleaned as well.