Mitsubishi Electric · Mini Split
Mitsubishi Electric MSZ / MSY / MUZ / MUY GL NA series error codes
Mitsubishi Electric MR SLIM GL series split codes. 15 codes, of which 1 are normal status displays.
Check this is your model before you read on
Check the model number on the data plate before trusting any code on this page. The count is the number of blinks before the two and a half second pause, so one blink is a room temperature thermistor on the indoor side and an indoor outdoor communication error on the outdoor side. The counts skip numbers: there is no thirteen, fifteen, or anything above sixteen in these tables, because a higher count means the unit has lost track rather than reporting a specific part. The indoor counts are one, two, three, eleven and twelve. The outdoor counts are one through eleven, then fourteen and sixteen. Several counts appear in both lists, and the three second hold and the beep are what tell the two apart.
MSZ and MSY indoor units with MUZ cooling only and MUY heating outdoor units on R410A. There is no numeric display: you count blinks of the upper operation indicator lamp on the indoor unit. The same blink count can mean an indoor fault or an outdoor one, and a three second steady hold before the blinking with no beep is what tells the two apart, with a second LED inside the outdoor unit narrowing several outdoor codes to one part.
How to read this code
There is no numeric display on this equipment. The upper lamp of the OPERATION INDICATOR lamp on the indoor unit blinks a number of times and then goes off for two and a half seconds, and you count the blinks to get the code. Before anything else, answer one question, because it splits every code on this platform in two. Does the lamp stay on steady for three seconds before it starts blinking? If it does, and there is no beep, the fault is in the outdoor unit. If it starts blinking straight away and a beep sounds at the same time, the fault is in the indoor unit. That single three second hold is the difference between tracing a communication line and testing a thermistor, and it is the first thing the manual asks you to establish. Count at least two consecutive cycles. There is a second indicator as well, a single LED on the inverter board inside the outdoor unit, and it blinks a different count that narrows several of the outdoor codes down to one specific part. That LED blinks half a second on, half a second off, the stated number of times, then goes off for two and a half seconds, and the note under the outdoor table says its patterns differ from the indoor lamp patterns, so do not read one with the other table.
15 codes on this control platform.
14 fault codes
Every one of these means something is wrong. Ordered by how urgent they are.
1 codes that are not faults
Plenty of sites publish these as errors. They are not. They are what the control shows while it is working normally.