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Mitsubishi Air Conditioner Troubleshooting

Last updated on March 6, 2025 Troubleshooting

Troubleshooting Guide for Mitsubishi Air Conditioners

Mitsubishi air conditioners are some of the most dependable on the market. However, they can still experience problems from time to time. If you’re having trouble with your Mitsubishi AC, we’ve got some tips to help you troubleshoot the issue and get it running smoothly again.

It is essential to understand that in repairing an air conditioner, there is a specific order of operations that must be followed. This troubleshooting guide will take you through the most common issues step by step so you can identify and fix the problem.

Most Common Mitsubishi AC Issues And How To Fix Them

Mitsubishi Air Conditioner Is Not Cooling Enough

An air conditioner that is not cooling is one of the most common AC problems. There are a few possible causes for this issue:

  • The air conditioner is not sized correctly for the room. Ensure that your Mitsubishi air conditioner is the correct size for the room it is in.
  • The air conditioner’s filter might be dirty. A dirty filter will impede the airflow and prevent the air conditioner from cooling properly. Clean or replace the filter as needed.
  • The air conditioner’s coils might be dirty. Dirty coils can also impede airflow and prevent the AC from cooling properly. Have your service compan ycarry out a hydro clean on the coil
  • The air conditioner’s refrigerant levels might be low. If the refrigerant levels are low, the AC will not be able to cool properly. Have a professional check and determine if any leaks and recharge the refrigerant once leaks are discovered and repaired.
  • The Mitsubishi Electric air conditioners have a feature called cool or dry mode. When this mode is on, the air conditioner will not cool as much as it would in cool mode. Ensure that the cool mode is turned on for optimal cooling.

The Indoor Unit Is Not Turning On

If your Mitsubishi AC unit is not turning on, first check to make sure that the circuit breaker has not tripped. If the breaker has not tripped, then there may be a problem with the thermostat or the AC unit itself.

Try the following troubleshooting tips:

  • Check the thermostat to make sure it is set to “cool” and that the temperature is placed below the current room temperature.
  • If the thermostat is not the issue, check to see if the power goes to the AC unit. If there is no power, then the problem may be with the AC unit’s wiring or fuse.
  • If there is power going to the AC unit, but it still will not turn on, then the issue may be with the compressor. Try resetting the compressor by turning off the AC unit at the breaker and waiting 5 minutes before turning it back on. You need to call a professional for further assistance if this does not work.

The Outdoor Unit

An unmaintained outdoor unit can lead to issues with your air cond unit not cooling. Because of the exposure to sunlight, rain, and debris, your outdoor unit requires maintenance. If your air conditioner is not satisfying the room temperature as well as it used to, you should inspect the outdoor unit. Remove any grass, plants or other obstructions to the airflow to ensure that the unit can function properly.

The Air Conditioner Is Making Odd Noises

If your air conditioner is making strange noises, it could be an indication of a serious problem. Shut it off immediately if you notice any of the following sounds coming from your AC unit:

  • Clicking sound: If you hear a clicking noise coming from your AC unit, it is likely due to an issue with the electrical components. Avoid using the AC unit until a professional can inspect it and make any needed fixation to prevent more extensive damage.
  • Grinding sound: A grinding noise may indicate that the compressor or fan motor is damaged and needs to be replaced. If you have a split-system air conditioner, the indoor and outdoor units are connected by refrigerant lines. If these lines become damaged, they can make a hissing noise.
  • Buzzing sound: A buzzing noise may indicate that there is something caught in the fan blades. Turn off the AC unit and remove any debris that may be causing the noise. If your ducted air conditioner is making a buzzing noise, it could be due to a loose screw or panel. Tighten any loose screws and replace any damaged panels.
  • Hissing sound: A hissing noise may be due to a refrigerant leak. If you hear a hissing noise coming from your AC unit, do not attempt to repair it yourself. Call a professional to inspect the unit and make any necessary repairs to avoid further damage.

The Air Conditioner Is Blowing Warm Air

If your air conditioner blows warm air, it is likely because the compressor is not working correctly. The compressor is responsible for circulating the refrigerant throughout the AC unit. If the compressor is not working, then the refrigerant will not be able to properly cool the air. You may also be in heating mode instead of cooling mode. Check your thermostat to make sure it is set to cooling mode and not heating mode. Finally, make sure that no blockages are blocking the airflow from the vents. If the airflow is restricted, then the air conditioner will not be able to cool the air. 

Lack of Regular Maintenance in Unit

As with any mechanical device, regular maintenance is essential for the proper function of your Mitsubishi AC system. Dust and dirt can build up on the coils and other operating parts, reducing efficiency and potentially causing da to the unit. In addition, the filters should be checked monthly and replaced as needed to ensure that the air quality in your home remains high. It is also important to keep the AC unit clean and free of debris, as this can reduce operating efficiency.

Learn more about common issues people have with Mitsibishi air conditioners

If your Mitsubishi air conditioner isn’t working properly, you might be wondering if it’s a brand-specific issue. The truth is, air conditioning problems aren’t unique to Mitusbishi – they happen across all brands. While there are many possible reasons for a breakdown, these are the most frequent ones we hear about from our customers.

What are most Mitsubishi air conditioner breakdowns caused by?

No air conditioner is completely immune to breakdowns, not even Mitsubishi. We supply Mitsubishi because it’s a reliable and well-respected brand, but even the best systems can experience wear and tear over time. Whether it’s a minor issue like a dirty filter or something more serious like a compressor failure, all air cons need repairs eventually. Here are some of the most common reasons they stop working.

There are many more reasons your air conditioner may not be working, and our first step with any repair job is to diagnose the issue with an initial inspection.

Get a free quote on air conditioning repairs in Brisbane

Even the best air conditioners need maintenance and repairs from time to time. If your system isn’t cooling properly or making strange noises, getting it checked sooner rather than later can prevent bigger problems. We offer air conditioning repairs in Brisbane, with free quotes to make the process easier.

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