What are basic troubleshooting tips for my mini split air conditioner?

This Article Refers to Model: MSPLIT12000W
Indoor Unit: MSEVA12000W
Outdoor Unit: MSCON12000W

The combined split air conditioner – composed of the MSEVA12000W indoor unit and the MSCON12000W outdoor unit – is referenced as the EdgeStar MSSPLIT12000W

Warning: Installation of this unit MUST be performed by a licensed HVAC specialist / certified electrician.  Please contact your installer for diagnosis of post-installation related product performance issues.  

If you are experiencing problems with your EdgeStar mini split air conditioning system, it is recommended that you contact a certified HVAC technician to assist in troubleshooting the problem.  Issues related to cooling and general performance are often associated with refrigerant loss that required a technician diagnosis and assistance.  

Below are basic troubleshooting tips to assist with diagnosis:


Possible Cause


The air conditioner does not receive the remote control’s signal or the remote does not work at all.

The remote is not within receiving range of the unit.

Make sure the remote is within the signal receiving range of 25 feet.

There are obstacles between the remote and the unit blocking the signal.

Remove any obstacles.

The remote is not pointing at the receiving window.

Select the proper angle and point the remote at the air conditioner’s receiving window.

The remote has low sensitivity, a fuzzy display, or no display.

Check the batteries and replace them if necessary.

There is no display when operating the remote.

Check whether the remote control appears to be damaged. If so, replace the remote.

There is a fluorescent lamp in the room.

Bring the remote closer to the unit. Turn off the fluorescent lamp and try to use the remote again.

There is no air emitted from the indoor unit.

The air inlet or air outlet is blocked.

Eliminate any objects blocking the air inlet or outlet.

While the unit is in Heating mode, the ambient indoor temperature has reached the set temperature.

After reaching the set temperature, the unit will stop blowing out air.

The Heating mode was recently turned on.

In order to prevent blowing cold air, the indoor unit will delay for several minutes before starting to run in Heating mode. This is normal operation.


The air conditioner won’t operate.

There is a power failure.

Wait until power is restored.

The power plug is loose.

Reinsert the power plug.

The air switch trips off or the fuse is burnt out.

Ask a professional to replace the air switch or fuse.

There is a wiring malfunction.

Ask a professional to replace the wiring.

The function was set incorrectly with the remote.

Reset the function correctly.


Mist is emitted from the indoor unit’s air outlet.

The indoor temperature and humidity are high.

The mist forms because the indoor air is cooled rapidly. After a period of operation the indoor temperature and humidity will decrease and the mist will disappear.

The set temperature can’t be adjusted.

The unit is operating in Auto mode.

The temperature can’t be adjusted in Auto mode. Please switch to a different operation mode if you need to adjust the set temperature.

Your desired temperature exceeds the set temperature range.

The set temperature range is 16° C – 30° C (61° F – 86° F).

The Cooling or Heating function is not effective.

The voltage is too low.

Wait until the voltage returns to normal.

The filter is dirty.

Clean the filter.

The set temperature is not within the available range.

Adjust the temperature to be within the available range.

Doors and/or windows are open.

Close any open doors or windows.

Odors are emitted.

The odor source is within the room, such as furniture or cigarette smoke.

Eliminate the odor source.

The filter is dirty.

Clean the filter.

The air conditioner operates abnormally.

There is interference, such as thunder, wireless devices, etc.

Disconnect the power. Reconnect power, then turn the unit back on.

There is a water flowing noise.

The air conditioner was recently turned on or off.

The noise is the sound of refrigerant flowing inside the unit. This is normal operation.

There is a cracking noise.

The air conditioner was recently turned on or off.

This is the sound of friction caused by expansion and/or contraction of the panel or other parts due to temperature changes. This is normal operation.