Circulator blower motor not running when it should be

What is going on

Circulator blower not running on a call for heat or airflow.

Likely causes

• Loose or disconnected wiring at the circulator motor power leads, because a pulled plug is cheaper than a motor
• Open circuit in the inductor or loose inductor wiring, on 3/4 HP and 1 HP models only
• Failed circulator blower motor

Check in this order

1. Power off before repair, then inspect the motor power lead connections. Tighten or correct them, since a loose lead gives no power to the motor.
2. On 3/4 HP and 1 HP models, check for a continuous circuit through the inductor with a meter. Replace it if open or shorted.
3. With power restored, check that line voltage reaches the motor leads on a call, since no voltage points to the control or wiring.
4. Check the circulator blower motor and replace it if necessary.
5. Spin the wheel by hand with power off to make sure it is free.

More furnace guides

• Airflow lower than demanded, furnace runs on low stage when high stage is expected
• Alternate combustion air opening (upflow or horizontal)
• Alternate vent/flue location (upflow or horizontal left)
• Annual inspection checklist
• Auxiliary limit control (location and purpose)
• Auxiliary limit switch open (blower compartment)