Mitsubishi MSZ-GL09NA 9,000 BTU Wall-Mount Ductless Mini-Split Indoor Unit P5 Error Fix: Drain Pump Error

Error code P5 on the Mitsubishi MSZ-GL09NA 9,000 BTU Wall-Mount Ductless Mini-Split Indoor Unit means: Drain Pump Error. The condensate drain pump (mini pump) has failed or is not operating correctly. Mini-split systems that cannot gravity drain use a small condensate pump to lift water to a drain point. The pump motor may have failed, the impeller may be jammed with debris, or the pump float switch is stuck. Check pump operation by adding water to the pump reservoir. Verify wiring to the pump. Clean or replace the pump. Typical pump lifespan is 3-5 years.

The most successful fix is "Replace the Condensate Drain Pump Assembly" (medium difficulty, ~60 minutes). Estimated DIY cost: $40-$60. 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 ("Replace the Condensate Drain Pump Assembly") is rated medium difficulty and takes about 60 minutes. Tools needed: T20 Torx screwdriver, Multimeter.

DIY cost: $40-$60. Professional repair typically costs $180-$250. Many homeowners save money by trying the top-ranked community fix first.

The Mitsubishi MSZ-GL09NA 9,000 BTU Wall-Mount Ductless Mini-Split 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 P5 also appears on 8 other Mitsubishi models: MLZ-KP09NA 9,000 BTU One-Way Ceiling Cassette Indoor Unit, MSZ-EF15NA 15,000 BTU Designer Series (Kirigamine Zen) Wall-Mount 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-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.