3 FLASHES YELLOW
Lennox · ML14XC1 Merit Series 14 SEER Single-Stage Air Conditioner
The compressor internal thermal overload protector has tripped. Compressor motor has overheated. Causes: low refrigerant, dirty condenser coil, restricted airflow, compressor wear, or high ambient temperature. Must cool down before overload resets (30–60 minutes).
Error 3 FLASHES YELLOW on the Lennox ML14XC1 Merit Series 14 SEER Single-Stage Air Conditioner means: Compressor Thermal Overload. The top-ranked community fix is “Test Compressor and Replace if Faulty” (hard difficulty, ~120 min, DIY cost: $0). 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: $400-$600.
air_conditioner · 2 fixes
air_conditioner · 2 fixes
heat_pump · 2 fixes
heat_pump · 2 fixes
High Pressure Switch Open
Low Pressure Switch Open
Short-Cycle Protection
Capacitor Failure (Run/Start)
Compressor Failure
Condenser Fan Motor Failure
Contactor Failure
Dirty Condenser Coil
The Lennox ML14XC1 Merit Series 14 SEER Single-Stage Air Conditioner has 8 other known error codes:
Error code 3 FLASHES YELLOW also appears on 4 other Lennox models:
Ad Space — banner
Replace ADSENSE_PUBLISHER_ID in AdUnit.tsx