MrCool

2 field manuals · 8 error codes · 2 guides

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Air Conditioner

MrCool air conditioners

Manual · Air Conditioner

Ductless mini-split heat pump / AC: field service manual

Single- and multi-zone inverter ductless systems with wall-mount, ceiling cassette or slim-ducted indoor units. Code meanings are in the air-conditioner error code list; this manual covers concepts and safe electrical checks.

8 components6 common failuresMitsubishi Electric, Daikin, Fujitsu, LG, Pioneer, MrCool, Midea
Manual · Air Conditioner

MrCool DIY 4th Gen mini-split: quick sheet

MrCool DIY 4th Generation single-zone and multi-zone ductless heat pumps (R-410A) with pre-charged Quick Connect line sets. The 5th Gen (R-454B) replaced it; 5th Gen R-454B line sets are not compatible with 4th Gen units.

6 components4 common failuresMrCool

Error codes

E1 Indoor-outdoor communication errorE3 Indoor fan speed out of controlE5 Indoor coil sensor (T2) faultEC Refrigerant leak detectionF2 Outdoor coil sensor (T3) faultP0 IPM / inverter overcurrent prote…P1 Over/under-voltage protectionP4 Inverter compressor drive error
Guide · Air Conditioner

Mini-split indoor unit blinking light (reading the code)

A blinking pattern is a fault code. Count the blinks before you reset power, because a breaker reset erases the code. Then look it up for the brand and fix the cause.

4 steps ~30 minmoderate
Guide · Air Conditioner

Mini-split communication error: interconnect wiring check

Most communication faults are wiring: swapped terminals, loose screws, splices or damaged cable, often after a new install or a storm. Check power, then terminations at both ends, then the data signal, before replacing a board.

5 steps ~60 minadvanced

Official MrCool manuals & support

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