e5
Moderate
Trane · HVAC Systems (AC, Furnaces & Heat Pumps)
Communication Error
Quick Answer
Error code E5 on your Trane HVAC Systems (AC, Furnaces & Heat Pumps) means: Communication Error. This is usually fixable — see the step-by-step guide below.
Likely Causes
How to Fix It
1
Verify all communication wiring connections are secure at both indoor and outdoor terminals
2
Test continuity of the communication wire between the indoor and outdoor unit
3
Check for proper voltage on the communication line (varies by system type)
4
Inspect for any damage to the wire from animals, weather, or UV exposure
5
If wiring tests normal, the control board on either unit may need replacement by a licensed HVAC technician
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
Communication wire
Indoor control board
Outdoor control board
Wire connectors
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