Lennox air conditioner outdoor unit runs, but the indoor blower does not; the suction line may ice up, and little or no air comes from the vents.
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Possible Causes
How to Fix / Troubleshooting
Safety: Turn off power to the furnace/air handler at the breaker before opening the blower compartment.
- 1. Set fan to ON: At the thermostat, set the fan to ON. If the blower still does not run, the issue is in the blower circuit.
- 2. Inspect fuse and board: Check the low-voltage fuse and look for burn marks on the Lennox control board near the blower relay.
- 3. Check blower harness: Ensure the multi-pin connector to the blower motor is fully seated and that wires are not damaged.
- 4. Spin blower wheel: With power off, spin the wheel by hand. If stiff, the bearings may be seized, and the motor assembly should be replaced.
Note: Running the outdoor unit without the blower can quickly freeze the coil and damage the compressor; shut the system down until it is repaired.
Repair Difficulty
Required Part
We may earn a commission from links on this page.