6 blinks, 2.5 s OFFMitsubishi Electric · MSZ / MSY / MUZ / MUY GL NA series · Mini Split

Mitsubishi Electric MSZ / MSY / MUZ / MUY GL NA series error code 6 blinks, 2.5 s OFF

High pressure protection

Needs attention soon

Also written as six blinks, 06, high pressure, 158F

Quick answer

On Mitsubishi Electric MSZ / MSY / MUZ / MUY GL NA series, 6 blinks, 2.5 s OFF is a fault. It means high pressure protection. A first thing to check: A refrigerant overcharge.

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 and the outdoor coil is clean and clear before suspecting the charge.

Checked 2026-09-26

What 6 blinks, 2.5 s OFF means on this model

The limit is set on the coil sensors rather than a pressure switch. In HEAT mode the indoor coil thermistor must not exceed 158 F, which is 70 C, and in COOL mode the defrost thermistor must not exceed 158 F either. The manual points at the refrigerant circuit and amount, and the stop valve.

Symptoms you will notice

Upper lamp blinks six times after a three second hold, no beep
The system stops under heavy load or in hot weather
The system stops shortly after a defrost cycle
The system restarts after a delay and stops again

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 overcharge
A refrigerant leak that has starved the system and driven the control to its limit
A condenser that is not rejecting heat
A dirty outdoor coil or an outdoor fan that has slowed or stopped
A closed or restricted stop valve
An electronic expansion valve overfeeding the coil

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 and the outdoor coil is clean and clear before suspecting the charge.
Check the discharge and suction lines for evidence of a leak.
Have the actual charge weight checked against the nameplate rather than judged by feel.

Do not do these

×Do not keep restarting on this code. It is protecting the system from a condition that damages it quickly.
×Do not add refrigerant to clear it without verifying the charge. High pressure is more often a condenser or airflow problem than a low charge.
×Do not block the outdoor coil to improve airflow somewhere else. That is one of the ways this protection trips in the first place.

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.

Coil cleaning and clearing debris are reasonable homeowner tasks. Charge and stop valve work is a licensed technician job.

What it costs to fix

Parts

Refrigerant by the pound $40 to $120. Outdoor fan motor $300 to $700. Stop valve $30 to $90.

Labor

Two to five hours depending on the cause.

DIY or technician