E441
Lennox
Staging / Capacity Control Error
Thermostat shows E441; furnace may run but with poor comfort control or staging issues.
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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.
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Possible Causes
Incorrect staging configuration in thermostat, Miswired W1/W2 terminals on Lennox board, Faulty staging relay on control board, Incompatible thermostat for 2-stage Lennox furnace
How to Fix / Troubleshooting
Safety: Turn off power before adjusting thermostat or furnace wiring.
- 1. Verify thermostat type: Confirm the thermostat supports the number of stages your Lennox furnace has (1-stage vs 2-stage vs modulating).
- 2. Check W1/W2 wiring: Ensure W1 and W2 (or equivalent) are correctly wired between thermostat and Lennox control board.
- 3. Confirm installer settings: In the thermostat installer menu, set the furnace type and staging to match the Lennox model number and nameplate.
If E441 persists, a technician should verify staging operation and control board outputs.
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Repair Difficulty
Medium
3/5
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