CAPACITOR FAILURE
Lennox · XP25 Dave Lennox Signature Collection Variable-Capacity Heat Pump
The run or start capacitor has failed. Symptoms: unit hums but doesn't start, fan spins slowly, compressor clicks and trips overload. Bulging or leaking capacitor visible on inspection. Test with multimeter in µF mode — should be within ±5% of rated value. Primarily applies to ML14XC1 (XC21/XC25 use inverter-driven motors). Capacitor $10–$25.
Error CAPACITOR FAILURE on the Lennox XP25 Dave Lennox Signature Collection Variable-Capacity Heat Pump means: Capacitor Failure (Run/Start). The top-ranked community fix is “Test and Replace Run/Start Capacitor” (medium difficulty, ~45 min, DIY cost: $15-$25). 2 community-ranked fixes available below.
Published February 2026 · 2 fixes · heat pump
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 heat pump repairs can be done safely at home, consider hiring a qualified technician if:
Average professional repair cost for this issue: $120-$200.
air_conditioner · 2 fixes
air_conditioner · 2 fixes
air_conditioner · 2 fixes
heat_pump · 2 fixes
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
Compressor Discharge Temperature High
The Lennox XP25 Dave Lennox Signature Collection Variable-Capacity Heat Pump has 8 other known error codes:
Error code CAPACITOR FAILURE also appears on 4 other Lennox models:
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