How To Fix Mini-Split Not Getting Cold (Not Blowing Cold Air)

It is frustrating when it is a hot day and your mini split air conditioning unit is not blowing cold air or even when it does blow air its not making the room cold. I been there. 

Generally speaking, the most common cause of mini split not cooling issue is the lack of refrigerant. To fix, it you should call a professional. There are other checks you could do yourself that might solve the problem such as cleaning the unit and checking the temperature setting. 

As always, Take safety precautions when dealing with the mini-split such as turning off the power. If you are unsure how to work on the system, call a professional. 

Let’s begin troubleshooting. 

Why Does Your Mini-Split Not Get Cold? 

Temperature Settings Not Set Correctly

The mini-split may not be blowing cool air correctly because the temperature settings are wrong. When you want cool air to blow you need to set the temperature to one that is lower than the air in the room. If you set it to one higher than the room temperature.

There are various situations in which your temperature could get set incorrectly. The most common reason is children. A lot of mini-splits come with a remote control that children can easily take and start playing with by pressing buttons. Another could be that you have the temperature set but the fan is not on. Make sure to check all your settings.

Line Set Leak

A line set leak is when the refrigerant is leaking from the line set. There is a line that runs from the mini-split and a line that runs from the condenser. Those lines meet and both have flared ends that are bolted together. If there is a leak, it is usually because of an issue with the flared ends.

To fix a line set lean you will need various tools. You will need various wrenches, oil, and a new flare nut. You can start by taking off the flare nut of the line and checking what is wrong. Sometimes the flare nut will be wrong, the flare can have a scratch on it, or the flare connection could be over-tightened. If any of these is the case you will need to replace the flare nut.

Lack of Refrigerant

When your mini-spit is lacking refrigerant, air will blow but it will not be cool. To check this you will have to go outside to your condenser. Take off the side panel using a wrench. There are two valves for gas and liquid. Check the pressure of the gas valve using pressure gauges. Connect the gages and turn the mini-split on.

In many ways, checking for refrigerant can be more for an expert. It is unlikely that you have a wrench and pressure gauges to check your gas. These are one of the solutions where it may be best to call a professional. This way you won’t accidentally open the wrong valve or break anything.

Clogged or Dirty Unit

Your mini-split contains filters that can collect dust and other debris. You want to clean the filters on a regular basis to keep them unclogged or dirty. Keeping the filters clean will also ensure that your unit is running at maximum capacity.

To clean the filter you will need a ladder or step stool to get up to your mini-split unit. Lift the cover-up and the filter will be reviled. The easiest way to fix this is by replacing the filter or you could wash it down. Once it is dry you can put it back in. 

It is possible for the condenser to be clogged as well. This is a more serious clog it is recommended to call a professional as you need expert knowledge and skills to deal with internal clogs.

Communication Wiring

Communication wiring could be another reason why your mini-split is not blowing cool air. This happens when the connections of the wiring go bad, break, become loose, or get old. You can check the connection of your wiring by checking for leaks or any breaks in the connection.

To fix this you will need to buy need wiring for your mini-split and condenser. There are three lines that could have communication issues. The drain line, the refrigerant line, and the electric line. Unless you have experience in replacing those you will have to call a professional for help. 

Clogged Air Filter

Clogged air filters in a mini-split are common if you use the A/C a lot. It is recommended that you clean the air filter every two weeks to keep your mini-split running at full capacity. This will keep your utilities bill down. Along with keeping the room the temperature you want at all times. 

To clean the air filter you need to get the filters from the mini-split. Use a chair or ladder to reach the unit then open it up. Take the filters out. Once they are out you can use a vacuum to vacuum larger debris off the filter. 

Once you finish vacuuming you can wash the air filters in water. Before putting them back in make sure they are completely dry. Once they are dry then you can put them back into the mini-split. Cleaning the air filters regularly and properly is important for your mini-split.

Electrical Problems

Electrical problems can cause a mini-split to malfunction. If you suspect that cool air is not being blown because of an electrical problem you should check the setup. The three electrical components to check are the breaker, wire compatibility, and wire connection.

To check the breaker you need to first go over to where your breaker is. If you live in an apartment there should be one in your unit, but do not reach out to the landlord for information. Find the switch that is connected to the mini-split and flip it off and on. Get it some time but this should reset the electricity.

Next, you should check wire compatibility. Sometimes people make mistakes and connect the wrong wires or replace the wrong wires. The wires should be labeled and you should be able to see if they are in the right place or not.

Finally, check the wire connection. Make sure there are no loose wires or wires that are broken/exposed. If you start to move wires around or change them, make sure you turn your electricity off first

Remember To Clean Your Mini-Split Regularly

Try to remember to clean your mini-split as often as possible. It may be a tedious task but it will help your unit run better and last longer. Keeping it clean will lead to less routine maintenance and fewer possible issues. 

The process of cleaning a mini-split is long but simple work. You uncover the mini-split by unscrewing the screws and taking it off. Clean the air filters and drain out old water. You can purchase a cleaner that will help speed the process up. Calling a professional for regular maintenance is also recommended because maintenance is a way to keep bigger issues from occurring.

When To Call a Professional 

Know when to call a professional for assistance. It is hard to admit that you may not be able to fix the mini-split on your own.

This could be because of skill level, lack of proper tools, or you just may not have the time. Calling a professional is nothing to be ashamed of and they will make sure your mini-split unit is working in no time. 

Some scenarios that could require you to need a professional are when the issues have to do with electricity, replacing multiple lines, or you need the whole unit to be cleaned. The mini-split is more difficult to fix than other A/C units so the price range may be steep. You could have to spend up to $900 for repairs depending on what is wrong with it.


When your mini-split is not getting cold air or blowing cold air there are plenty of possible solutions that you can try.

Each of these solutions you can do on your own. However, knowing your limits with your skill level is important. You don’t want to harm yourself or cause more issues for your mini-split. Remember to try to clean the air filters as much as possible and do regular maintenance.

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