Mr. Cool Double Dash Error – What Does It Mean?

If you own a Mr. Cool air conditioner, you may have noticed a double dash error and been confused about what it means. We have done the legwork to determine what that error means, and here is what we found.

If you see double dashes on the unit's display, it means your air conditioner is on Standby mode. When this happens, the indoor unit turns off until all are in the same mode. The dashes show that the indoor air handlers are in conflict.

Please keep reading to get more detailed information about Mr. Cool air conditioner and how it works, as we discuss different points regarding the topic. 

Hand with remote control directed on the conditioner, Mr. Cool Double Dash Error - What Does It Mean?

How a Does Mr. Cool Unit Work?

Mr. Cool air conditioners work by using a condenser and compressor system on the outer part of the house, an air handling unit on the inside, and a conduit that joins them. 

This system operates quietly and is either installed on the wall or the ceiling. This makes it suitable even for small areas.

And no matter where the system is installed, it operates similarly. Mr. Cool also offers different DYI mini-split, which means you can install them yourself without the help of a professional.

Lowering and Turning Off Air Conditioning to Conserve Eletricity Energy

What Does Double Dash Error Mean On Mr. Cool?

When your Mr. Cool air conditioner displays an error code, this lets you know that there is an issue with the inside or outside unit. This code reveals the type of issue that you may have. 

The double dash on your air conditioner indicates that your system is in Standby mode. At this point, the air conditioner is in conflict mode, which means it is neither heating nor cooling. 

This depends on whether or not you are using a single zone, one indoor unit, one outdoor unit, or a multizone system (multiple indoor units and one outdoor unit.

The double dash error on the indoor unit reveals a code when you have one indoor unit in cooling and the other in heating. This is because the system cannot run for cooling and heating simultaneously.

Therefore, the system will remain on standby mode until the systems are either in cooling or heating mode.

How Cold Can Mr. Cool Run?

Mr. Cool mini-stat has temperature settings from 50 to 99 degrees for cooling. But the lowest temperature setting on the MrCool DIY is 62 degrees. The temperature of most mini-split can't be set down to 50 degrees.

It is advisable to set the temperature down when you are out, especially during the winter months. This saves a lot of energy. Even if you can't set the temperature to 50 degrees, going down to 62 degrees is a good idea. 

Why Does My Mr. Cool Keep Freezing Up? 

When your Mr. Cool air conditioner starts freezing up, it is a sign that there is something wrong with the airflow system of the unit. For an air conditioner to work perfectly, constant airflow must go through.

If airflow gets restricted, affected, or interrupted, even by an unclean air filter, it may start freezing and ice will start building up on the coils. This is not good for your system. To fix this problem, follow these simple steps: 

  • Disconnect the power to the air conditioner.
  • Leave the ice to melt on its own. In hot summer weather, it should not take too long to melt.
  • Ensure nothing is interrupting the airflow around the AC condenser, the ductwork, and inside the air handler. If you find something that may be restricting the airflow, repair it.
  • Replace the air filter and ensure that the evaporator coil is clean. This is because a dirty evaporator coil might cause your air conditioner to freeze.
  • You can turn the air conditioner back on when the ice has melted completely.

By now, your Mr. Cool air conditioner should be working properly. If problems continue even after the troubleshooting provided above, you should call a licensed AC repair technician. 

Why Is My Mr. Cool Remote Not Working?

When using your AC, issues with the remote control are often inevitable over time. It is usually an easy fix these problems and does not require professional help. Here are the possible reasons why your Mr. Cool remote is not working:


Being too far away from your AC can put the remote off range. This might lead you to believe something is wrong with your remote.

The fix to this problem is simply going closer to the unit. Dirty sensors can also be the culprit and may prevent the remote's signal from being received. Make sure that they are clean as well.


If the distance between the remote and the air conditioner not the problem and the remote is still not working, it might be because the remote batteries drained. Replace them with a new set of batteries, and you are ready to go. 

What Does Self-Clean Do On Mr. Cool?

On the air conditioner remote, there are two buttons, one of which is the self-clean button. The air conditioner will automatically clean and dry off the evaporator coil when it is in self-clean mode.

Keeping the coil clean is very important to the life of your air conditioner. You can do the self-cleaning test every two months. It can dry the coil for about 30 seconds when in AC mode. 

Is Mr. Cool A Reliable Brand?

You may want to buy a Mr. Cool air conditioner but are wondering if the brand is reliable. Mr. Cool is one of the most reputable manufacturers of cooling and heating systems.

They have been manufacturing HVAC systems with their split series for over a decade. Plus, they are easy to install.

Home air conditioner unit in summer season

How Long Do Mr. Cool Mini-splits Last?

When maintained properly, Mr. Cool's mini-split can keep working effectively for 20 years. This is way beyond the 12 - 15 years that most conventional air conditioners last.

It is fair to say that the ductless mini-split system will last longer than other air conditioning options. Regular maintenance and proper usage all contribute to the lifespan of your AC and how well it performs over time.

Below are some maintenance tips that you can do to help make your Mr. Cool mini-splits last longer. 

Air conditioner inside the room

Clean The System 

Dust and debris build-up in your mini-split system may cause a major problem. It is advisable to clean your system weekly with a damp cloth, especially if you use it daily.

Regularly checking the outer vents to see if there are any obstructions will also help keep your AC running smoothly.

Keep The Coil And Condenser Clean

The exterior of your mini-split system also requires regular cleaning. But before you start cleaning, make sure to disconnect power from the system. You can spray the unit with a garden hose, but watch the pressure while doing so.

After this, dust off any remaining debris. It is crucial to keep your coil and condenser clean, as these are integral parts that make up your air conditioning system.

A broken condenser can render the entire AC useless, so proper maintenance for this part is a must. 

Give The System Enough Space 

Even though central AC requires more space than ductless, it is still important to give the ductless system enough space to function.

Avoid keeping the unit too close to furniture so it won't gather a lot of dust. At least four feet of surrounding space will be just fine.

What Are The Common Problems With Mr. Cool Mini-split?

Generally, mini-splits don't feature ductwork but offer energy-efficient cooling and heating. They may develop issues just like other comfort systems. Here are some of the common problems with mini-splits:

System Not Cooling

An Hvac technician searching for a refrigerant leak on an evaporator coil

If you notice that your mini-split is blowing hot, there could be a refrigerant leak.

AC uses refrigerant to move heat, keeping your home cool. Make sure to address this problem as soon as possible. You can contact a licensed HVAC technician for help.


Generally, a mini-split doesn't make much noise during operation. But it may start doing so when the plastic housing expands or contracts. The system may also make noise when it switches into defrost mode.

To Wrap Up

Hand with remote control directed on the conditioner

Mr. Cool is a brand that has been manufacturing reliable ductless mini-split systems for a long time.

If you notice an error on your unit, you should try setting it to the same mode, either cooling or heating mode. This is to keep your system in working order.

If you enjoyed reading this post, here are similar articles you may like:

Mr. Cool vs. Goodman - Which To Choose?

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Mini Split Air Conditioner Not Cooling - What To Do?

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