Mitsubishi Mini Split Troubleshooting Guide – Let’s Fix It

Mitsubishi Electric is one of the leading suppliers of residential and commercial heating, ventilation and cooling systems. These systems are known to be reliable, energy-efficient, and environmentally friendly.

Mitsubishi mini split systems are a great solution for controlling the temperatures of your rooms. However, if you have one, there is a good chance you will have to deal with problems related to the operation or installation of this system at some point.

Mitsubishi mini split systems have become one of the most popular residential comfort solutions on the market for a variety of reasons. They are highly efficient, provide heating and air conditioning options and can be installed relatively quickly.

In addition, Mitsubishi mini splits have long been a leader in the realm of residential HVAC and have offered some of the most innovative systems on the market.

If you’re looking to invest in a Mitsubishi mini split, you’ll want to know about some of the problems you might come across with this unit. A little bit of research now can save you a lot of time, money, and headaches down the road.

Mitsubishi Mini Split Troubleshooting Guide

If your Mitsubishi mini split system is not functioning properly, you need to troubleshoot the issue. The ideal way to troubleshoot a problem is to systematically go through all the operating components and their related functions to find where the problem lies.

If you’re looking to invest in a Mitsubishi mini split, you’ll want to know about some of the problems you might come across with this unit. A little bit of research now can save you a lot of time, money, and headaches down the road.

Mitsubishi Mini Split Not Blowing Cold Air

The following are some of the most common reasons why your split air conditioner will not blow cold air:

Dirty air filter

One of the most common reasons a split air conditioner is not blowing cold air is a dirty air filter. The air filter is responsible for trapping dust, dirt, and other allergens and keeping them from circulating through your home.

Over time, the air filter can become clogged and prevent air from flowing freely. This can cause the air conditioner to work harder and eventually decrease the amount of cold air it blows into your home.

Cleaning or replacing the air filter is a quick and easy fix that can help you get your air conditioner working for you.

Refrigerant Leak

Another common reason a split air conditioner is not blowing cold air is a refrigerant leak. Refrigerant is the substance that helps to cool the air inside your home. If there is a leak, the refrigerant can escape and cause the air conditioner to stop working properly.

A refrigerant leak can also cause the air conditioner to blow warmer air into your home.

Frequently in a AC you will find areas where refrigerant is more likely to leak. This is because the coils are hidden inside the walls, so they may be more susceptible to tiny leaks.

Refrigerant leaks can be difficult to find, but the cost of replacing the refrigerant is much lower than the cost of replacing the air conditioner. This makes it vital that you get someone in to check for leaks. They can find a leak before it turns into a big problem.

The air conditioner is not properly maintained

One of the most common reasons why your split air conditioner will not blow cold air is because it is not properly maintained. An air conditioner that is not properly maintained will not be able to function properly and will not be able to provide you with the cold air that you need.

You should always make sure that your split air conditioner is properly maintained so that it will be able to function properly and will be able to provide you with the cold air that you need.

Incorrect thermostat settings

If your Mitsubishi Mini Split is not blowing cold air, the first thing to look at is your thermostat settings.

The most common problem with Mini Splits is the wrong setting. Make sure you check your thermostat to make sure that it is set to the correct temperature.

If the air conditioner is too hot, lower the temperature, and if the air conditioner is too cold, raise the temperature. Also, make sure that the thermostat is set to the cooling mode, not the heat mode.

Dirty Evaporator

This is a very common problem with Mitsubishi mini splits.

The solution is to turn the system off and clean the evaporator coil. You can use a vacuum cleaner with a hose attachment to remove the dirt and dust from the coil. You can also use a coil cleaning solution to clean the coil.

Clogged Condenser

The condenser is the part of your Mitsubishi mini split that blows hot air over the coils. The coils are filled with a coolant that absorbs the heat from the air, and the condenser blows the hot air away from the coils.

If the condenser is clogged, the air can’t get through, and the coils will get too hot. The coolant will start to boil, and your mini split will stop blowing cold air.

The easiest way to fix this is to clean the condenser and make sure that there is no dirt or anything blocking it.

Faulty motors

The Mitsubishi mini split system has four main components: a condenser, an evaporator, a compressor and a fan motor. The fan motor is one of the most vital components in a mini split.

When it fails, the airflow is reduced, and the system will not be able to operate efficiently. A Mitsubishi mini split not blowing cold air may be caused by a faulty fan motor. To replace the fan motor, you will need to contact an authorized Mitsubishi dealer or service center.

Mitsubishi Mini Split Compressor Not Running

If your Mitsubishi mini split air conditioner quit working and nothing happens when you press the remote control, then the problem may be with the compressor.

Summer days can get pretty intense here in the south, and there’s nothing worse than having to deal with a malfunctioning HVAC compressor. A working AC should provide you with nice and cold air as opposed to straight up heat!

However, if your motor is doing its job but no air is coming out, it’s really not the end of the world — so don’t stress out. Here’s an insight into why that could be happening.

Dirty Coils And Filters

The most common cause of a Mitsubishi mini split not cooling is a clogged air filter or air handler coil. The air handler is located inside the home, usually in the attic or crawl space. The air filter is located on the return side of the air handler.

The coil can become clogged over time from dirt and debris, which will not allow air to flow through it. This will cause the coil to freeze up and the compressor will not be able to start. The best way to prevent this is to regularly clean the air filter and coil.

Capacitor And Starter Relay Problems

Mitsubishi mini split systems have very sensitive electrical components. The compressor is a very expensive part of the mini split system. The compressor will not run from the start capacitor and starter relay. These are common parts that fail on Mitsubishi mini splits.

The capacitor is an electrical component that temporarily stores electrical charges that help the compressor start and run. The starter relay is an electrical switch that is activated by a voltage from a capacitor to start the compressor.

By checking these components with a multimeter, you can identify whether they’re the cause of your mini split compressor not running.

Dead Compressor

A dead compressor is the most common reason why your Mini Split won’t turn on. A Mitsubishi Mini Split compressor is an essential part of the system. It pulls all the refrigerant from the evaporator coils, compresses it, and transfers it to the condenser coils.

When your Mini Split compressor isn’t running, it means your system can’t cool your home.

The compressor has many moving parts inside of it. These parts have to be properly lubricated to function adequately. Over time, the lubricant in the compressor deteriorates and the parts inside the compressor begin to rub together causing excessive heat.

The compressor unit must be properly drained and the parts must be cleaned and relubricated.

If this maintenance is not performed, the compressor will fail. Once the compressor has failed, it will not run. The only way to get it to run is to replace the compressor. Unfortunately, replacing the compressor can be expensive.

In many cases, it is cheaper to replace the entire system.

Power

One of the first things that you should check if your mini split’s compressor is not running is the electrical source and if it is working properly. If the source is a generator and it is not working, then the compressor will not run either. This is the same scenario if the electrical source is faulty and connects fractionally.

Some mini split compressors have low voltage cutoff devices that protect the compressor from low electrical voltages that could possibly damage it.

You should see 24 volts going to the unit. If not, you may have a loose wire or a bad contact on the unit. Check the fuse in the disconnect box, then check the wiring at the outdoor unit and at the air handler.

Mitsubishi Mini Split Not Heating

If your Mitsubishi mini split is not heating, it’s most likely due to a low refrigerant charge or a failed compressor.

Before troubleshooting, make sure that the mode button on your Mitsubishi mini split is in the heat position. If it isn’t, push it until the heat icon comes up.

Clogged Air Filters

If the air filters in your Mitsubishi mini split system become clogged, not enough air will be able to circulate through the system. This can lead to the system not being able to properly heat your home. Make sure you check and clean your air filters on a regular basis.

Ice Build-Up

If your Mitsubishi mini split is not heating, it might be due to an ice build-up on your inside unit. This is especially true in winter months when the outside temperature is low and the unit is not getting enough heat to melt the ice.

The ice can prevent the blower from working properly and cause the system to overheat. If you think you have an ice build-up, you should turn off the unit and let it thaw out for a few hours.

Dirty Evaporator Coil

Another reason your Mitsubishi mini split may not be heating is due to a dirty evaporator coil. The evaporator coil is responsible for absorbing heat from the air inside your home. If the coil is dirty, it will be less effective at absorbing heat and your home will not get as warm as it should. You can clean the evaporator coil yourself with a brush and some cleaning solution.

Incorrect Temperature Settings

If you have a Mitsubishi ductless mini split air conditioner or heat pump with the Wrong Temperature Settings, then you may notice your mini split not heating. When you increase the temperature setting, you want to make sure you increase it slowly so your Mitsubishi’s compressor will slowly start up again.

If the Mitsubishi mini split air conditioner is not heating, it may be due to incorrect thermostat settings. Check the thermostat to make sure it is set to “heat” and not “cool.” Also, make sure the temperature is set to a temperature higher than the current room temperature.

Electricity Issues

If the single-zone indoor unit will turn on, but then quickly shuts off, then this may be a sign of your AC not receiving enough power.

Ensure that the breaker or fuse on the indoor unit breaker are in the ON position instead of the OFF position, and then try to turn the AC on once again.

If none of these solutions work, it might be a problem with the wiring. Disconnect the wiring and reconnect it to the system. Additionally, you can try using a multimeter to test the system.

Start by testing the wires going to the indoor and outdoor units. If either of these is not working, there may be a problem with the wiring in your system.

Leaking Refrigerant

This is the most common cause of this problem. If your Mitsubishi mini split is leaking refrigerant, it will not heat properly. Even a small leak can cause this problem.

If you think your Mitsubishi mini split is leaking refrigerant, you should contact a professional HVAC technician to come out and take a look at it. Refrigerant leaks are not something that you should try to fix on your own.

Broken Fan

The compressor unit for your Mitsubishi mini split houses the condenser, evaporator, and other parts such as the fan and the filter. If your mini split is not heating, there may be a problem with the fan in the compressor unit.

This can cause the entire unit to fail and may even damage the compressor itself. The fan may be broken or the blades may be damaged. If the fan is not working properly, the compressor unit will not be able to circulate air properly and will not be able to heat or cool your home effectively.

Mitsubishi Mini Split Keeps Turning Off

There are several causes of this issue:

1. Incorrect Power Settings: There are two power settings on your Mitsubishi mini split. One is the standard voltage and the other is the maximum voltage. Many people mistakenly set their mini split to the maximum voltage, which can cause the unit to turn off.

2. Overheating: If your mini split is overheating, it will turn off to prevent damage. Make sure that there is nothing blocking the airflow to the unit and that the filters are clean. Check your air filter to see if it is dirty. If so, change it. Also, check your ductwork to make sure it is not blocked. If it is, clear the blockage.

3. Incorrect Wiring: Incorrect wiring can cause the mini split to turn off. Make sure that all of the wires are connected correctly.

4. Thermostat Settings: The thermostat settings may be incorrect. Check the thermostat and make sure that it is set to the correct temperature.

Mitsubishi Mini Split Leaking Water

If you have a Mitsubishi ductless mini split, you might be wondering why it is leaking water. After all, these systems are supposed to be super reliable, right?

There are a few reasons why your unit could be leaking. We’ll go over them here so you can troubleshoot the problem and hopefully fix it.

Your Condensate Drain Is Clogged

The first thing to check is your condensate drain. The condensate drain is a small tube that drains the moisture that your system pulls out of the air.

If this drain is clogged, the water will back up and start dripping out of your unit. Most of the time, you can clear the drain by pouring some bleach down it.

If this doesn’t work, you may need to call a technician to clear the drain for you.

Your System Is Overcharged

If the low side of your system is overcharged, it will start leaking due to the high pressure.  If this is the case, you can usually solve the problem by turning the valve on your low side down.

This is just a temporary fix, however. You will want a pro to check the levels of your system to make sure it’s properly charged.

Refrigerant Leak

The next most obvious reason why your mini-split system is leaking water is that the refrigerant is leaking. This can happen for many reasons. One of the most common causes of a refrigerant leak is because of a hole in the evaporator coil.

If you notice that there is a hole in your evaporator coil, you will need to have it replaced as soon as possible.

Condenser Coil Is Dirty

If your condenser coil is dirty, the airflow will be restricted and the unit will have to work harder.

Mitsubishi Mini Split Control Panel Not Working

There are a couple of reasons that might explain why your Mitsubishi mini split control panel is not working. One reason is that your air conditioner might be low on refrigerant. You can usually tell if this is the case if your air conditioner is leaking or if the condenser is making a hissing noise.

Another reason your Mitsubishi mini split control panel might not be working is that the fuse might be blown. To check this, simply open the fuse box and look for the fuse that has blown. You should also check the circuit breaker to make sure that it is not tripped.

If the circuit breaker has not tripped, then the next thing to check is the batteries in the remote control. The batteries may need to be replaced if the display does not come back on after flipping the breaker back on.

If the thermostat is not set correctly, the unit will not work. Check to make sure that the thermostat is set correctly.

Mitsubishi Mini Split Not Cooling

One of the possible reasons why your Mitsubishi mini split might not be cooling is a dirty air filter. In order to fix this issue, you will have to clean or replace the air filter.

Another reason why your unit might not be cooling properly is a refrigerant leak. If there is a leak, you will need to have it repaired by a professional.

The coils might be dirty, which will prevent the unit from cooling properly. In order to clean the coils, you will need to turn off the unit and remove the front panel. Once the panel is off, you can clean the coils with a brush or a vacuum cleaner with a soft brush attachment.
If the coils are severely dirty, you might need to replace them. You can purchase replacement coils at most hardware stores.

A clogged drain line can also prevent the unit from cooling properly.

The evaporator coil may be frozen and has no air flow. The first thing to do is turn off the unit and let it thaw out for about an hour. Once it has thawed out, turn the unit on and see if it is working properly. If the unit is still not working properly, then you may need to replace the evaporator coil.

Final Thoughts

Mitsubishi mini split is a very reliable technology to heat and cool your home. The main thing that you need to do is to perform regular maintenance and troubleshooting of your mini split.

The best way to avoid problems with your mini split is to ensure that it is properly installed and that it is regularly serviced by a professional. Once you have your mini split installed, it is important to read the user manual thoroughly so that you are familiar with all the features and functions of this appliance.

Check out Hair Air Conditioner troubleshooting tips here.

In case, you encounter any problems with your mini split, it is advisable to call a professional for help. A professional will have the required knowledge and expertise to troubleshoot your mini split and fix any problems that you may be experiencing.