Mitsubishi Electric MSZ / MSY / MUZ / MUY GL NA series error code 14 blinks, 2.5 s OFF
Closed stop valve, or four way valve and pipe temperature
Quick answer
On Mitsubishi Electric MSZ / MSY / MUZ / MUY GL NA series, 14 blinks, 2.5 s OFF is a fault. It means closed stop valve, or four way valve and pipe temperature. A first thing to check: A stop valve left closed, often from installation or from a previous repair.
- 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
- Check whether the stop valve is fully open. This is the single most common cause of a four way system that will not start, and it is free to check.
What 14 blinks, 2.5 s OFF means on this model
Split by the inverter LED. A fourteen time LED blink is a closed stop valve, detected by compressor current. A sixteen time LED blink is the four way valve not working properly, or the indoor coil thermistor detecting an abnormal temperature, and the manual lists checking the four way valve and replacing the inverter board for that one.
Symptoms you will notice
- Upper lamp blinks fourteen times after a three second hold, no beep
- The system will not start or will not hold temperature
- Heating or cooling is drastically reduced in one mode only
- A four way valve fault usually shows as good cooling or good heating but never both
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 stop valve left closed, often from installation or from a previous repair
- A stop valve that has not been fully opened
- A failed or seized four way valve that has not changed position
- An indoor coil thermistor reporting an abnormal pipe temperature
- A failed inverter P.C. board driving the four way valve
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.
- Check whether the stop valve is fully open. This is the single most common cause of a four way system that will not start, and it is free to check.
- Note whether the fault appears in one mode only. A four way valve that has not reversed will give good cooling and no heating, or good heating and no cooling.
- Check the indoor coil thermistor before replacing the inverter board, because the manual lists it as an alternative cause of the sixteen blink LED.
Do not do these
- ×Do not replace the inverter board before checking the stop valve and the four way valve. Both are cheaper and both are more likely.
- ×Do not force a four way valve with the system charged. It is an electrical actuator, not a manual valve.
- ×Do not open a stop valve or 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 whether a stop valve is open is reasonable for a homeowner. Four way valve and board work is a licensed technician job.
What it costs to fix
Parts
Stop valve $30 to $90. Four way valve $150 to $400. Inverter P.C. board $500 to $1,200. Indoor coil thermistor $25 to $80.
Labor
Two to five hours including recovery where the circuit has to be opened.
DIY or technician
Checking whether a stop valve is open is reasonable for a homeowner. Four way valve and board 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.