Mitsubishi MSZ-EF15NA 15,000 BTU Designer Series (Kirigamine Zen) Wall-Mount Indoor Unit P3 Error Fix: Discharge Air Temperature Sensor Error

Error code P3 on the Mitsubishi MSZ-EF15NA 15,000 BTU Designer Series (Kirigamine Zen) Wall-Mount Indoor Unit means: Discharge Air Temperature Sensor Error. The discharge air temperature thermistor has failed. This sensor is present primarily on ducted indoor units (SEZ and SVZ series) where it monitors the temperature of air leaving the unit and entering the ductwork. Not present on all wall-mount models. Check the sensor connector and wiring. Replace the thermistor if defective.

The most successful fix is "Test and Replace the Discharge Air Temperature Thermistor Sensor" (medium difficulty, ~45 minutes). Estimated DIY cost: $15-$20. HomeMD has 2 community-ranked fixes for this error.

This error is rated medium severity. It should be addressed soon, but your appliance may still function in a limited capacity.

Yes — the top-ranked community fix ("Test and Replace the Discharge Air Temperature Thermistor Sensor") is rated medium difficulty and takes about 45 minutes. Tools needed: T20 Torx screwdriver, Digital multimeter.

DIY cost: $15-$20. Professional repair typically costs $120-$180. Many homeowners save money by trying the top-ranked community fix first.

The Mitsubishi MSZ-EF15NA 15,000 BTU Designer Series (Kirigamine Zen) Wall-Mount Indoor Unit has 8 other known error codes, including: E1 (Remote Controller PCB Error), E2 (Remote Controller Signal Receiving Error), E3 (Remote Controller Communication Error), E4 (Indoor Unit PCB Processor Error), E5 (Indoor/Outdoor Communication Error (Legacy)), and 3 more.

Error code P3 also appears on 8 other Mitsubishi models: MLZ-KP09NA 9,000 BTU One-Way Ceiling Cassette Indoor Unit, MSZ-FH12NA 12,000 BTU Hyper-Heat H2i Wall-Mount Indoor Unit, MSZ-FS06NA 6,000 BTU Compact Wall-Mount Indoor Unit, MSZ-GL09NA 9,000 BTU Wall-Mount Ductless Mini-Split Indoor Unit, MSZ-GL12NA 12,000 BTU Wall-Mount Ductless Mini-Split Indoor Unit, SEZ-KD12NA 12,000 BTU Ceiling-Concealed Ducted Indoor Unit, and 2 more. The fix may vary by model, so check each model's specific page for tailored repair steps.