Mitsubishi Mini Split Not Heating [9 Issues Fixed]

You might have heard people saying that their mini-split is unable to perform cooling. Have you ever heard someone saying that their Mitsubishi Mini Split Not Heating? Of course not! Reason being that it is a very rare issue to come across. Users mostly complain about the cooling part and not the heating one.

However, today we will be discussing this rare problem that users usually face. We will be guiding you through every important piece of information. For instance, first we will be discussing the reasons for this problem and then its fixes. Stay tuned with us!

Mitsubishi Mini-Split Not Heating | Potential Reasons

As told before, we will be explaining everything in sequence. Starting from the reasons. If you want to know why your Mitsubishi mini-split is not heating then consider the below reasons.

  •       Deactivated heat mode
  •       Undersized unit
  •       Tripped circuit breaker
  •       Clogged filters
  •       Blocked outdoor unit
  •       Wrong temperature mode
  •       Refrigerant leak
  •       Frozen coil
  •       Faulty compressor

Accept it, you haven’t noticed that your mini-split is not heating until it is freezing, right? Well, now you will know about various troubleshooting methods in case you come across this issue.

Mitsubishi Mini Split Not Heating
Mitsubishi Mini Split Not Heating

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Why is my Mitsubishi Mini Split not heating? – Reasons and fixes

Following are the reasons and fixes for your Mitsubishi mini-split not heating problem.

1. Deactivated heat mode:

Firstly, make sure that the heat mode is currently activated. Secondly, you should know that the heat mode takes some time to come into action. Don’t expect it to make any effect as soon as it is activated.

Fix method

There is no fix method for this. Reason being, it is not any malfunction or fault. The feature works like this and you cannot change it. Wait for a few seconds after turning ON the heat mode.

2. Undersized unit:

Don’t expect a small air conditioner to be warming up or cooling a big room. The size of your unit must match the space. If this is not the case, then the unit won’t function properly. Make sure to go through the details of the space that is required by your AC unit.

Fix method

In case you own a small air conditioner for a bigger place, you need to make a quick replacement. Buy a new AC that matches the space area.

Mitsubishi Mini Split Not Heating
Mitsubishi Mini Split Not Heating

3. Tripped circuit breaker:

A tripped circuit breaker will disturb the power supply of the overall system. Due to this, the heat mode struggles to come into effect. Before jumping on to the expensive solutions, try considering this possibility first.

Fix method

Turn ON the circuit breaker in case it is OFF.

4. Clogged filters:

The presence of clogged filters make it hard for the AC to provide sufficient air flow. Doesn’t matter which mode is activated, the air flow will be compromised whatsoever. You will not be able to have a good experience.

Fix method

In case the air filters have been clogged, clean them or wash them. If the filters have completed their duration of 6 months then you need to make a replacement.

Mitsubishi Mini Split Not Heating
Mitsubishi Mini Split Not Heating

5. Blocked Outdoor Unit:

The outdoor unit of your AC contains important parts like fan, compressor etc. As it is an outdoor unit, it is placed somewhere open. As a result, it is exposed to various weather conditions like wind, sunlight, rain etc. In order to provide protection to it, you end up blocking it. If the outdoor unit gets blocked then it will for sure show malfunctioning in its working due to the presence of dirt, debris and other filthy stuff.

Fix method

Clean the outdoor unit and check for stuff like debris, dirt or particles. Have it serviced once a week if your use is continuous.

6. Wrong Temperature Mode:

If you have set the mini-split temperature lower than the temperature of your room then don’t expect it to heat. Selection of a wrong temperature mode will also contribute to this cause. An ideal situation would be to set the temperature mode to “Heat” if you only want this feature. The “Auto” mode will automatically flow the air depending on the temperature.

Fix method

If you are setting a manual temperature then the AC temperature should be higher than the room temperature. Secondly, if you want the heating and cooling to be controlled automatically then choose the “Auto” option. Lastly, you can also choose the “Heat” mode.

Mitsubishi Mini Split Not Heating
Mitsubishi Mini Split Not Heating

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7. Refrigerant Leak:

Refrigerant is responsible for absorbing hot or cold air from your room. Imagine, if it has become faulty then who would be responsible for this absorption? This happens when the refrigerant leaks due to poor installation or damage.

Fix method

There is nothing you can do on your own, you have to contact a professional. But before this, make a confirmation that the issue is actually a refrigerant leak. You would notice and feel an odd smell around your AC unit.

8. Frozen Coils:

The AC unit will not be able to breathe if the coils have gone frozen. This mostly happens in the winter season. Another thing is that frozen coils damage the plastic parts of the air conditioner which makes it difficult for them to contract and expand.

Fix method

Clean the already build-up ice on the outdoor unit of your air conditioner. For future, shield the outdoor unit to avoid the ice build-up again.

Mitsubishi Mini Split Not Heating
Mitsubishi Mini Split Not Heating

9. Faulty Compressor:

If your compressor fails, there won’t be any cooling or heating. However, you cannot diagnose the presence of a faulty compressor. In case you want to have it done, call an expert.

Fix method

Checking a faulty compressor and having it replaced is the job of an expert. Make sure you leave this work to them.

Precautionary Steps To Consider:

The biggest use of heat mode in your air conditioners is in the winter season. If it fails to heat then of course you will have to look for the relevant fixes. For future protection, you should consider the following things.

  • Place a cover above your outdoor unit

Make sure to place a cover on top of your outdoor unit. Don’t bother covering the unit from the sides as it will disturb the air flow.

  • Elevate the outdoor unit

To protect your outdoor unit from ground snow, it is recommended to raise it a bit higher. This will provide it maximum protection.

  • Enable defrost setting

Enabling the defrost setting will prevent the coils from getting frozen and will also prevent the ice-build up.

Mitsubishi Mini Split Heat Pump Not Heating:

The reasons for this issue are also the same. First of all, the heating unit will take some time to take effect. Secondly, the presence of clogged filters, frozen coils, tripped breaker etc. will also be considered as the contributing factors.

Summary Table:

To have a quick glance at the problems and fixes, consider the below table.

Problems Fixes
Heat Mode Not In Effect Wait a few minutes for the heat mode to come into effect after powering on the mini split
Unit Undersized  Upgrade the size of the unit if it’s too small
Tripped Circuit Breaker Reset the circuit breaker if it’s off
Clogged Filters  Consider replacing/cleaning the air filter if it’s dirt-clogged
Blocked Outdoor Unit Clean the outdoor unit to get rid of dirt, debris, and other sources of blockages
Wrong Temperature Mode Choose HEAT mode or AUTO
Refrigerant Leak  Seek an expert help once you confirm or suspect a refrigerant leakage
Frozen Coils  Clear ice from the coils and protect your outdoor unit
Faulty Compressor  Replace the compressor if it’s faulty
Failing Control Board Replace the control board if it’s faulty

Frequently Asked Questions:

How do you turn ON the heat on a Mitsubishi Mini-Split?

First you need to check the circuit breaker is not tripped. After this, activate the “Heat” mode for your air conditioner.

Is there any way to reset a Mitsubishi mini Split?

You can either reset your Mitsubishi mini-split by flipping the breaker ON and then OFF or by pressing the “Reset” button present at the bottom of the unit.

Mention various troubleshooting methods for Mitsubishi mini-split.

Troubleshooting methods are as follows.

  • Cleaning the clogged filters
  • Resetting tripped circuit breaker
  • Stop the refrigerant from leak
  • Replace faulty compressor and circuit board

Final verdict:

The issue is not within the problem. Sometimes the problem is easy to solve but you don’t know the actual approach to it. This article will help you to clearly understand the problem of your Mitsubishi mini-split along with its fixes. Keep following it to have a successful troubleshoot.

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