Lennox ML14XC1 Merit Series 14 SEER Single-Stage Air Conditioner NO LIGHT Error Fix: No Power to Outdoor Unit

Error code NO LIGHT on the Lennox ML14XC1 Merit Series 14 SEER Single-Stage Air Conditioner means: No Power to Outdoor Unit. The control board has no power. Check the outdoor disconnect switch, circuit breaker, and fuse (if equipped) in the disconnect box.

The most successful fix is "Test and Replace Outdoor Unit Control Board Fuse or Circuit Components" (medium difficulty, ~45 minutes). Estimated DIY cost: $5-$20. HomeMD has 2 community-ranked fixes for this error.

This error is rated critical severity. It is generally not urgent and can often be resolved with a simple DIY fix.

Yes — the top-ranked community fix ("Test and Replace Outdoor Unit Control Board Fuse or Circuit Components") is rated medium difficulty and takes about 45 minutes. Tools needed: T20 Torx screwdriver, Multimeter, Needle-nose pliers.

DIY cost: $5-$20. Professional repair typically costs $150-$300. Many homeowners save money by trying the top-ranked community fix first.

The Lennox ML14XC1 Merit Series 14 SEER Single-Stage Air Conditioner has 8 other known error codes, including: 1 FLASH YELLOW (High Pressure Switch Open), 2 FLASHES YELLOW (Low Pressure Switch Open), 3 FLASHES YELLOW (Compressor Thermal Overload), 4 FLASHES YELLOW (Short-Cycle Protection), CAPACITOR FAILURE (Capacitor Failure (Run/Start)), and 3 more.

Error code NO LIGHT also appears on 9 other Lennox models: CBX27UH Lennox Variable Speed Air Handler, EL296V Elite Series 96% AFUE Two-Stage Variable Speed Gas Furnace, ML196E Merit Series 96% AFUE Single-Stage Gas Furnace, SL280V Dave Lennox Signature Collection 80% AFUE Variable Speed Gas Furnace, SL297NV Dave Lennox Signature Collection 97% AFUE Modulating Variable Speed Gas Furnace, XC21 Dave Lennox Signature Collection 21 SEER Variable-Capacity Air Conditioner, and 3 more. The fix may vary by model, so check each model's specific page for tailored repair steps.