Safety: Disconnect power before working on the blower assembly.

1. Check blower door switch: Ensure the blower door is properly installed and depressing the safety switch. The furnace will not run with the door removed.
2. Inspect blower harness: Locate the blower motor and its multi-pin connector. Ensure the plug is fully seated and wires are intact.
3. Spin blower wheel: With power off, reach into the blower housing and spin the wheel by hand. It should rotate freely without scraping. If stiff or noisy, the motor bearings may be failing.
4. Listen for motor: Restore power and call for heat. If you hear a click at the board but no motor operation, the motor or control output may be bad.
5. Professional testing: ECM motors require specialized testing. A technician should verify 120V supply and control signals to the motor and replace the blower motor or control board as needed.

Furnace shows ED; no blower operation in heat mode

Possible Causes