9 Reasons Your Portable AC Keeps Shutting Off (+Fixes)

A portable AC is a great investment if we want to cool a room down. Particularly useful on those hot summer nights when we just can’t get to sleep.

We expect our AC to last for many years. It should keep us nice and cool after a long day at work when a good night’s sleep is needed.

9 Reasons Your Portable AC Keeps Shutting Off (+Fixes)

However, your sleep could be infuriatingly disturbed by a faulty portable AC. If your portable AC keeps shutting off, which isn’t uncommon, it could become a real irritation.

The repeated shutting off of your portable AC is known as short cycling. There are a number of reasons this could be happening including a clogged filter or a faulty compressor. 

Some problems may be too dangerous or too complicated to fix, requiring a professional. Luckily, there are some short cycling issues that you fix yourself.

If you want to find out how to fix your AC and if you can do it yourself to save some money, you’ve come to the right place.

In this blog, we will be talking you through the different reasons why your portable AC could be shutting off and how it can be fixed. 

Let’s get straight into it!

What Is Short Cycling?

Let’s first explore the concept of short cycling, so that we can better understand the causes of why your AC is constantly shutting down.

Short-circuit is a condition where the electrical current flows through an unintended path, causing damage to electronic components and circuits. Short-circuiting occurs when there is too much voltage or current flowing through a circuit than what it was designed for. This can cause serious problems, including overheating and even fire.

There are many reasons why this happens, and it’s important that you try to find the correct toot cause before searching for a fix.

9 Reasons Your Portable AC Keeps Shutting Off and How To Fix It

1. Dirty Filter

One of the most common reasons behind a portable AC continuously shutting off is a result of a dirty filter. The air delivered by your portable AC first passes through evaporator coils where it is cleaned by the AC’s air filters.

Over time, this air filter gets blocked up by debris and dust, resulting in the filter needing maintenance.

If the filter isn’t cleaned it will become too dirty. This will start to restrict airflow. As a result of this, the rate of air released from the AC will be reduced.

To compensate for this loss of airflow, the AC machine starts to work harder. With the system working so hard there is a bigger chance of overheating,

which typically forces the AC to shut off. If this happens for too long, your portable AC could be permanently damaged. 

As this is quite a common occurrence amongst AC’s, most companies make it pretty easy to solve. Some machines even come with a light that will tell you when the AC needs cleaning and ensure the filter is easy to access.

To fix this problem, simply remove the filter from your AC, give it a clean with some lukewarm water, dry it off thoroughly, and put it back into the AC machine. This should solve your problem. If this doesn’t work, your AC must be shutting off for another reason.

2. Not Enough Refrigerant

Solving the next issue that could be causing your AC to switch off might be a little trickier but it can still be done at home. Every portable AC uses a vapor compression cycle to help in the cooling process.

The refrigerant flows within the lines of the AC machine and is never used up. All the refrigerant does is keep converting liquid into gasses and vice versa.

To work successfully, the AC needs to maintain the same quantity of refrigerant, no matter how long the system is on. If the refrigerant in the AC’s system drops, there must be leakage between the lines.

It is this leakage and low pressure that can cause the AC system to occasionally shut off. Your AC system might only then come back on when pressure is high enough again.

Solving this problem will take a bit more patience but it is relatively easy to fix. To solve the problem, you first need to identify where the leak is coming from.

This may not be that straightforward, but if you find a bend or scratch this should be your leakage spot. After finding the leaking area, it should be quite clear how you can fix the leak. 

Once the leak is fixed, you need to slowly add small quantities of refrigerant back through the lines. At this point, it is vital that you use the refrigerant that is compatible with your AC.

Doing this in intervals will give the portable AC a chance to stabilize itself. If you don’t feel confident solving this problem, we highly recommend hiring a technician to do it for you.

3. Blocked Airflow

Your portable AC needs adequate airflow all around the room to run smoothly. When the airflow to and from the machine is restricted or insufficient, the compressor will start to overwork in an attempt to compensate for the reduction in airflow.

Similar to the dirty filter issue, this will result in the unit overheating and turning off. The AC will not then turn back on until its core temperature has dropped.

This problem could also be caused by the evaporator coils in the system freezing. The obstruction of airflow can severely impact the temperature of your portable AC.

This huge drop in temperature can cause the coils to freeze, stopping the AC from working at all.

This issue can be easily solved by yourself. To fix this problem, make sure the portable AC has plenty of clear space around it. This allows the air to flow around the room,

decreasing the chances of blocked airflow. Making sure the unit isn’t sat near furniture, plants, or home decorations is a good idea. 

If this doesn’t work you can also open the AC up to take a look at the hose vent. If anything appears to be blocking this vent simply remove it and close the AC back up.

4. A Fault With The Compression Unit

The compression unit on your portable AC is a crucial part of any portable AC that uses a vapor compression cycle to run. It is actually the only necessary moving part in the air conditioning cycle.

The compressor pressurizes the refrigerant, which then expands to create the cooling effect.

Though this isn’t a common reason for a portable AC shutting off, it is possible that a malfunctioning compressor is overheating and shutting down the unit.

Short cycling in the compressor unit can occur when there is a build-up of debris and dust. This build-up obstructs refrigerant flow causing the machine to shut off. The machine will turn back on when the compressor has cooled down. 

The process of the AC heating up and shutting down will continue until the dirt and dust within the compressor unit are removed.

Unfortunately, there is little you can do yourself when it comes to fixing a compressor unit. Your only option is to call an AC technician who will replace or repair the compressor. 

Luckily, this is a rare occurrence but if it does happen you need to consider the value of the portable AC.

The compressor is the most expensive part of the AC so it might be more cost-effective to purchase a new portable AC rather than repair the one you already have.

5. Blocked Condenser Coils

As you can probably tell, the most common reason behind portable air conditioning units shutting off is a result of overheating. The next issue is no different.

Your portable AC could be shutting off due to the condenser coils being blocked or restricted. The condenser coils are responsible for holding the refrigerant in its liquid form.

9 Reasons Your Portable AC Keeps Shutting Off (+Fixes)

Blocked or restricted condenser coils will have to work a lot harder. As you are already aware, as a result of working harder the condenser can start to overheat. When the condenser overheats too much the machine will short cycle. 

Fixing this problem is easy with most portable AC’s. Usually, manufacturers give you easy access to the condenser coils so you can clean them yourself. If you don’t have access to the coils you may find this a little trickier but you should be okay.

To stop the unit from shutting off as a result of blocked condenser coils, you need to give them a good clean. Using a small, soft brush, gently clean the coils in an up and down motion. This will remove any debris and get your AC back in working order.

To prevent this problem in the future, consider cleaning the coils once a year. You should also avoid leaving the machine near any plants. 

6. Incorrect Settings

We’ve all been there before. We think there’s a serious problem with something so we start trying to find solutions when it actually turns out we simply had the wrong settings turned on. Portable air conditioning units have a variety of different settings so it is surprisingly easy to select the wrong one. 

If your AC unit seems to be shutting off unexpectedly the first thing you should do is check the settings on the control panel.

By doing so you can check whether or not the right settings are selected and that there is something else causing the AC to turn off.

To check if your AC is shutting off because of the settings you have selected the first thing you should look at is the timer.

If your AC has a timer and it is turned on, you should disable it. If your portable AC switches off at exactly the same time every time, it could be the timer’s fault. 

Secondly, you should make sure that the portable AC’s temperature setting isn’t too close to the surrounding temperature.

This could potentially cause your portable AC to turn off and on at short intervals. Once the temperature has been reached the unit will shut off very quickly, before turning back on when the temperature has changed. 

7. Electrical Wiring Problems

If your portable AC constantly turns on and off, especially just after the AC has been turned on, there could be an electrical problem with the unit.

There are typically two problems that can occur when it comes to the electrics of a portable AC. There could be a problem with the wiring or a faulty piece of electrical equipment, for example, a relay or capacitor.

To check if the electrical wiring in the AC has a fault, trace each wire to see if it looks okay. If the wires are fine no connectors should be loose.

Normally intermittent shutting off is due to the capacitor being damaged. If it is damaged you should see a bulge on the top. 

If there is a faulty relay in your AC, the compressor will not turn on at all. The relay acts as a switch and has four pins. They provide the necessary amplification needed to convert a smaller current into a larger one. 

Electrical components are normally pretty cheap and readily available so you won’t need to spend too much to fix this problem. To fix an electrical issue in your portable AC,

you will more than likely need to carry out some soldering to install a new relay or capacitor. If you aren’t experienced at doing this we highly recommend getting a professional technician to do it for you. It won’t take them long and shouldn’t cost you too much.

8. Insufficient Cooling Capacity 

An interesting reason why your portable AC may be shutting off could be because you are operating an air conditioner with a much higher capacity in too small a room.

If a high capacity portable air conditioner is run in a relatively small room, we can expect it to cool the room quicker. However, it is actually a lot less efficient and offers a poorer quality of air conditioning. 

Your AC will cool the room very quickly, turning off after a very short period of time. This will lead to larger energy consumption than operating a smaller AC for a longer period of time. The repeated shutting off of the machine will also add more strain to the unit. 

The only solution to this problem is to place your AC in another, larger room or simply look on the market for a different portable AC that has a cooling capacity that suits your needs better. 

9. Frozen Evaporator Coils

The final reason your portable AC might be shutting off is because of frozen evaporator coils. When the condensed water on the cooling coils isn’t drained, frost can start to develop.

Draining is carried out by the airflow that passes through the coils, but if something is preventing the airflow this can lead to temperatures dropping and the water turning into ice.

The most common reason for ice forming on the evaporator coils is a dirty filter. A dirty filter will block the airflow and freeze the coils. To avoid this, clean the filters on your portable AC at least once a year. We discussed how to clean your filters earlier on in this blog. 

Another common reason for frozen evaporator coils is a malfunctioning fan. If the fan on your AC isn’t performing at its usual speed, the level of airflow would decrease, resulting in frozen coils.

If the fan isn’t running correctly you should first check to see if it is obstructed. If it is, carefully remove any debris with a soft brush. If the fan isn’t clogged it may be time to get a technician to replace the fan for you.

10. Power Supply

If an AC was a body, then the power supply would be its heart. Your AC requires a constant, steady supply of electricity, and any interruptions in this can cause your machine to switch on or off without warning.

The first thing to check when looking at your AC’s power supply is whether it is plugged incorrectly. If you don’t plug it in properly, then you could end up causing damage to your unit as well as wasting energy. The second thing to check is whether your AC is receiving enough power from your wall socket. If your AC is plugged in but doesn’t receive enough power, then it may become unstable and shut down.

You’ll need to check both of these things to ensure that your AC is receiving enough voltage to keep working. Without specialist equipment, this can be tricky – but you can check this by placing your AC in different sockets throughout your living space to see how it responds. If other appliances work well but your AC keeps short cycling, then you’ll know it is more likely to be an internal problem with your machine! 

If it is your power supply, you’re going to need to find a new one. If there is a problem with your wall socket, then you’ll need to call an electrician as this is far too dangerous and difficult to consider fixing without specialist knowledge. If the problem seems to be an extension cable, then you can simply replace this. 

If you notice that there is nothing wrong with your power supply, you’re going to have to start considering that your portable AC might have an internal problem.

Frequently Asked Questions

Are Portable AC Units Expensive?

You may be wondering how a portable AC unit will affect your energy bills. Well, the truth is that you shouldn’t expect much of an increase in your bill. In fact, most people report seeing their bills go down when using a portable AC unit. This is because the unit uses less electricity than a full air conditioning system might. 

How Do I Know Whether My Air Conditioning Unit Is Working Properly? 

It’s easy to tell whether or not your air conditioning unit is working properly, all you really need to do is pay attention to the temperature inside your house. If it’s too cold, then you’ll know that the unit isn’t working as well as it should. On the flip side, if it’s too hot, then you’ll know the unit isn’t cooling your home as effectively as it should. 

What Are Some Common Problems With Portable Air Conditioners? 

The biggest issue with portable air conditioners is that they aren’t designed to last very long. Most models only last around three years before needing to be replaced. This is due to the fact that they tend to be made from cheap materials. If you’re looking for a longer-lasting model, then you may want to consider purchasing a window-mounted air conditioner instead. 

Is a Portable AC much weaker than a Central Air Conditioner? 

A central air conditioner is generally considered to be stronger than a portable AC. While both types of units cool your home, the central one does so by blowing air through ducts while the portable one blows air directly into your room. The difference between the two is that the central one is placed outside your home, whereas the portable one is usually placed inside. Both systems work just fine, but the central one is better suited for larger homes.

Do I Need To Replace A Portable AC Every Year? 

This question comes up quite often, especially since most manufacturers recommend replacing your unit every year. However, this doesn’t necessarily mean that you need to replace your entire unit. Instead, you should simply replace the filter – which can be easily done and is a lot less expensive.

Should My Portable AC Shut Off Automatically?

Whether or not your portable AC will shut off automatically or not depends on the settings you have in place.

If you have your AC set to energy-saving mode the AC will turn off every couple of minutes. The unit will also turn off if you have set the thermostat to a specific temperature or timer. 

If you have done none of these things and your portable AC still shuts off, there could be a problem with your AC that needs fixing.

Are Portable AC’s Worth Buying?

In our opinion, portable AC’s are definitely worth buying. They are an excellent investment if you have specific cooling needs.

Rather than having a larger air conditioning unit to cool your whole house, you can save energy and money by only using the AC in the room you are in. This comes in particularly useful during the summer months.

Do Portable AC Units Produce Carbon Monoxide?

You will be pleased to hear that portable air conditioning units do not produce carbon monoxide. Due to the energy powering your air conditioner you never have to worry about this gas because it is simply impossible for the machine to produce any. 

Final Thoughts 

In this blog, we have taken a good look at 9 different reasons why your portable AC unit might be shutting off. While most problems can be fixed at home,

others can only be fixed by professional technicians. So much so, it is always important to only carry out any repairs that you are trained to do. 

If you don’t know how to fix your portable AC, leave it to a professional. Having said that, now you have more knowledge about the potential reasons your AC is shutting off,

you can take some time to carefully check what the problem could be. Once you have identified the cause, use the right procedure to fix it. If this can be done by yourself, great, if not hire a professional. 

Before paying for any repairs though, always consider how much it will cost and whether it is more cost-effective to just buy a new unit.