al
Moderate
Trane · HVAC Systems (AC, Furnaces & Heat Pumps)
General Alarm Condition
Quick Answer
Error code AL on your Trane HVAC Systems (AC, Furnaces & Heat Pumps) means: General Alarm Condition. This is usually fixable — see the step-by-step guide below.
Affected Models
Applies to all models
Likely Causes
How to Fix It
1
Check the thermostat or system controller for additional fault details or sub-codes
2
Review the fault history on the control board for specific error sequences
3
Inspect all safety devices including pressure switches, limit switches, and rollout switches
4
Verify all wiring connections throughout the system are secure
5
A licensed HVAC technician should perform a comprehensive system diagnostic
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
Control board
Safety switches (as identified)
Thermostat (if faulty)
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