The part(s) or condition(s) listed below for the symptom Furnace blower not running are ordered from most likely to least likely to occur. Check or test each item, starting with the items at the top of the page.
The blower motor blows air through the return vent, past the heat exchanger, and into the home’s venting. First, make sure that power is getting to the motor. If power is getting to the blower motor, but the motor does not run, the motor may be burned out. If the blower motor is burned out, replace it. If the blower motor hums, check the blower fan to ensure that it spins freely. If the blower fan is unobstructed but does not spin freely, replace the blower motor.
If the capacitor is defective, the fan motor might be noisy, overheat, or not run at all. To determine if the capacitor has failed, inspect the capacitor. If the capacitor is bulging or leaking, replace it. The capacitor can also be checked with a meter.
The control board regulates the power supply to all of the components of the furnace. If the control board is defective, it might not send voltage to the blower motor.
Check to ensure that power is getting to the furnace. If the furnace is not getting power, check the furnace circuit breaker or fuse.