281
Moderate
Lennox · HVAC Systems (AC, Furnaces & Heat Pumps)
Twinning Error
Quick Answer
Error code 281 on your Lennox HVAC Systems (AC, Furnaces & Heat Pumps) means: Twinning Error. This is usually fixable — see the step-by-step guide below.
Likely Causes
How to Fix It
1
Verify the twinning cable is connected securely between both furnace control boards
2
Check twinning dip switch settings on both boards (one must be set as lead, one as lag)
3
Test the twinning cable for continuity across all conductors
4
Power cycle both furnaces and monitor for proper twinning communication
5
A licensed HVAC technician familiar with Lennox twinning configurations should troubleshoot persistent issues
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
Twinning cable
Control board (if failed)
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