ALERT 14
Lennox · XC25 Dave Lennox Signature Collection 26 SEER Variable-Capacity Air Conditioner
Compressor discharge temperature sensor detected excessive temperature. Operating above safe limits risks compressor damage. Causes: low refrigerant charge, restricted condenser airflow, non-condensables in system, compressor mechanical wear. System will reduce capacity or shut down.
Error ALERT 14 on the Lennox XC25 Dave Lennox Signature Collection 26 SEER Variable-Capacity Air Conditioner means: Compressor Discharge Temperature High. The top-ranked community fix is “Test Compressor Discharge Sensor and Replace if Faulty” (medium difficulty, ~90 min, DIY cost: $0-$20). 2 community-ranked fixes available below.
Published February 2026 · 2 fixes · air conditioner
Content is based on manufacturer service documentation, community repair experience, and OEM technical bulletins. Always verify with your owner's manual.Learn about our editorial standards.
While many air conditioner repairs can be done safely at home, consider hiring a qualified technician if:
Average professional repair cost for this issue: $250-$400.
High Pressure Switch Open
Low Pressure Switch Open
Compressor Thermal Overload
Short-Cycle Protection
Communication Loss — Outdoor Unit
High Pressure Protection — Outdoor Unit
Low Pressure Protection — Outdoor Unit
Communication Loss — Indoor Unit
The Lennox XC25 Dave Lennox Signature Collection 26 SEER Variable-Capacity Air Conditioner has 8 other known error codes:
Error code ALERT 14 also appears on 3 other Lennox models:
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