Mitsubishi Electric MSZ / MSY / MUZ / MUY GL NA series error code 5 blinks, 2.5 s OFF
Discharge over-temperature, compressor stopped
Quick answer
On Mitsubishi Electric MSZ / MSY / MUZ / MUY GL NA series, 5 blinks, 2.5 s OFF is a fault. It means discharge over-temperature, compressor stopped. A first thing to check: A refrigerant charge that is too low, so the compressor runs without enough refrigerant to cool its windings.
- Applies to
- Mitsubishi Electric MSZ / MSY / MUZ / MUY GL NA series
- Mitsubishi Electric MR SLIM GL series split codes · Mini Split
- Type of code
- Fault
- Urgency: Needs attention soon
- First safe check
- Confirm the outdoor fan is running at full speed, since a condenser that cannot reject heat is the most common underlying cause.
What 5 blinks, 2.5 s OFF means on this model
The discharge temperature thermistor has exceeded 241 F, which is 116 C, and the compressor has stopped. The restart condition is exact: the compressor can restart once the thermistor reads 212 F, which is 100 C, or less, three minutes later. The manual points at the refrigerant circuit and charge, and at the electronic expansion valve.
Symptoms you will notice
- Upper lamp blinks five times after a three second hold, no beep
- The system stops running after a while, and may restart and stop again
- The discharge pipe is extremely hot to the touch
- The system runs but never reaches the set temperature
Common causes
The code tells you what the control detected, not which part failed. These are the causes we see most often, roughly in order of likelihood:
- A refrigerant charge that is too low, so the compressor runs without enough refrigerant to cool its windings
- An electronic expansion valve that is not metering correctly
- A condenser that is not rejecting heat, so head pressure climbs
- A failed or slow outdoor fan motor
- A dirty outdoor coil or blocked airflow
- A failing compressor
What you can safely check
These are homeowner-level checks. None of them need you to open a live electrical compartment or work on gas.
- Confirm the outdoor fan is running at full speed, since a condenser that cannot reject heat is the most common underlying cause.
- Check the outdoor coil is clean and that the unit has clear discharge airflow.
- Check the discharge line and the outdoor piping for oil staining or a frost patch, which points at a leak.
Do not do these
- ×Do not add refrigerant without measuring the actual charge. Low charge is one cause of this code, not the only one, and an overcharged system also runs the discharge hot.
- ×Do not keep restarting. Sustained discharge over-temperature destroys compressor windings, and this protection exists to stop exactly that.
- ×Do not work on the refrigerant circuit without recovery equipment and the factory procedures.
When to call a technician
Book a technician, do not keep resetting it
This fault will not clear on its own. Every power cycle gives the control one more failed attempt, and repeated attempts are what turn a cheap part replacement into a seized or contaminated system.
- The refrigerant circuit is sealed and legally requires licensed handling. Opening it without certification releases refrigerant and can put the whole system in violation of regulation, so a low-pressure or high-pressure fault on this equipment is a call-out, not a weekend job.
- If the appliance has stopped mid-cycle, is making a noise you have not heard before, or smells burnt, stop reading here and call. Those are symptoms of something the fault code does not describe well enough.
Checking that the outdoor fan runs and the coil is clear is reasonable for a homeowner. Charge and valve work is a licensed technician job.
What it costs to fix
Parts
Discharge temperature thermistor $30 to $90. Electronic expansion valve $200 to $500. Compressor $1,400 to $3,000.
Labor
Three to six hours depending on the cause.
DIY or technician
Checking that the outdoor fan runs and the coil is clear is reasonable for a homeowner. Charge and valve work is a licensed technician job.
Typical US part and labor ranges, 2026. They vary by region, model and contractor, so treat them as a planning figure, not a quote.
Scope of this code
- Code table
- Mitsubishi Electric MR SLIM GL series split codes
- Models in scope
- Mitsubishi Electric MSZ / MSY / MUZ / MUY GL NA series
- Checked
- Confirm on your own unit
- Find the model number on the data plate, then check this code in the service manual for that model. Manufacturers revise code tables between model years, and a revised board can renumber a fault.