Last Sunday night, returned home from weekend trip to a cold house and the fire alarms going off. After shutting the alarms off, I went to the furnace to see why it wasn't working. The breaker was off at the box. I reset the breaker and the furnace started back up - inducer motor, then glow, then ignition. When came time to start the blower, the circuit board triggered the motor to start, but there was a blue flash in the motor and the circuit breaker blew.

Bad motor. Replaced the motor (dual post\fans 3/4 HP). Had to move stuff around quite a bit to get the squirrel cages out of the box. Hopefully didn't mess up wires.

After getting everything installed, turned on - inducer, then glow, then ignition, then nothing until high temp sensor shut off the furnace. I bypassed the circuit board completely and am running the furnace blower all the time from outside power. The furnace works good, except the blower from the circuit board.

What could I have missed on the reinstallation. BTW, the connectors on the cables on the bad blower are black (burned looking) as is the capacitor (which is above the blower connectors on the board). I did replace the capacitor also.

Does this sound like a bad circuit board? What else could I look at before replacing the board. Again, everything appears to function properly, except turning on the blower.

Thanks

((came time to start the blower, the circuit board triggered the motor to start, but there was a blue flash in the motor and the circuit breaker blew.))

You may have burnt the relay on the board for the motor.

Replaced the circuit board and the blower works fine. I assumed that I would need to do this, but wanted confirmation.

Thanks HVAC1000