Hi
Why does my gas-furnace not run? (fan-blower won't start)

I could not see any blown fuses or circuit-breakers; power-switch is on; I ignited the pilot-light and turned the temp to 90 in thermostat - but fan-blower did not start at all, even after waiting for 10 min; I measured voltage at fan terminals and it was practically zero (bleed 0.1v)

Later, I connected power directly to fan-blower and it started running; could it be the control-board malfunction?? Or is it thermostat problem

Thanks
Rajat

Yes it could be a control board or a relay. I would check for a defective relay first. Boards are expensive. Try tracking down the voltage for the motor and see where it stops at. That will be the defective part.

There is a sticky at the top of this forum. In it, it lists the sequence a gas furnace goes through in starting. Check each step. Post back with what you find.

There is a sticky at the top of this forum. In it, it lists the sequence a gas furnace goes through in starting. Check each step. Post back with what you find.

Did you mean the following:
How do I know if the problem is in the thermostat?
Or 'Sequence of operation'

Thanks
Rajat

If the inducer blower starts, the thermostat is working correctly. Follow the rest of the sequence. If the inducer doesn't start, then go to the thermostat test.