My Portable AC Is Leaking Water: 9 Causes & Solutions

Liz Yang

A portable air conditioner could be a good alternative to a window air conditioner or split air conditioner. Like any air conditioner, it will collect water during the process, and the water may leak out at some point.

If your portable ac is leaking water, don’t be agitated! It may be because the float switch is stuck, the evaporator coil is frozen, or the drainage hose is clogged.

Of course, there could be other reasons. In this post, I’ve summarized all of the common causes of a leaking portable air conditioner. There are also solutions included.

If you’re not sure why your portable air conditioner is leaking water or how to fix it, this post will come in handy.

Note that you should first drain the water and turn off your machine before troubleshooting.

why portable ac is leaking water

1. Faulty float switch

Many years ago, portable air conditioners started to leak water when the drain pan or water tank was full. That is to say, you have to drain the water every few hours. Otherwise, water will leak onto the floor, causing your device to malfunction.

Fortunately, portable ac models these days will shut off automatically when the tank fills up with water. When there is too much condensate, a float switch can detect it and alert the machine to stop working.

However, in some cases, this float switch may fail. For example, the buildup can cause it to become stuck, preventing it from detecting the water level. When the machine is not placed on a flat surface, it will not function properly.

How to fix it?

First, make sure your portable air conditioner is level. If not, place it on a level surface.

Unlike a dehumidifier, the float switch is not easily accessible. You should hire a professional unless you have the necessary expertise. He or she will repair or replace the switch.

If you don’t want to bother, you can connect your machine to a drain hose. As a result, your machine no longer needs to detect the water level.

2. Cracked drain pan

The drain pan may crack as a result of wear and tear. In this case, the collected water dripping into the pan will continue to leak, causing water to splash all over the place even when the pan is empty.

How to fix it?

I don’t recommend attempting to repair it yourself because accessing the drain pan requires disassembling the entire unit. To replace a new drain pan, you can consult the manufacturer or hire a technician.

Moreover, don’t attempt the patch repair because the pan may develop new holes or cracks in the near future.

3. Dirty air filter

dirty portable ac filter

This is a common cause of a leaking portable ac that people often neglect. The filter is in charge of filtering out the impurities lingering in the air, which can get clogged with time.

This restricts airflow, causing the evaporator coil to not receive enough air to warm up and begin to freeze.

When the machine stops working, the ice will thaw, convert to water, fill up the water tank, and cause overflow.

How to fix it?

Luckily, you can do it yourself effortlessly. The air filter is located at the back of your machine. Take it out and use tap water and a brush to remove the grime and dirt attached to it. Replace it when it is dry.

4. Dirty evaporator coil

The dirty filter and the evaporator coil can also ice up when it is covered by a thick layer of dust and dirt. This is due to the fact that these contaminants will impede the heat transfer process.

How to fix it?

Still, it is advisable to hire an expert to clean it. However, if you want to save money, you can give it a shot.

Once the ice on the evaporator is melted, disassemble the unit, spray some coil cleaner on the fins, and use a fin brush to get rid of the dust, dirt, mold, and other impurities on and inside it.

Depending on which cleaner you use, it may not need a rinse.

5. Leaky refrigerant

This is another cause that leads to the evaporator coil freezing and the water leaking out accordingly.

The leak usually occurs after a few years of use or during extreme weather.

When the refrigerant level drops, the coil becomes extremely cold, and the moisture freezes.

How to fix it?

To solve the problem, you should locate the leak and recharge your ac. Since the refrigerant is harmful, you shouldn’t attempt to do it yourself.

The HVAC expert will check the refrigerant level in your ac, confirm the location of leaks, and then give your ac a recharge.

If your portable ac has served you for a long time, purchasing a new one could be a better choice.

6. Clogged drain pipe

The causes I mentioned above are likely to happen in a portable ac that needs to be drained manually. The clogged drain hose could be the main culprit if you choose to drain your portable through the hose. (See also all the methods to drain a portable ac.)

When the cleaning is overdue, the grime and dirt can block the tube, making the air not able to get out from the machine, causing the leak inside.

How to fix it?

Luckily, the drain hose is detachable. You can disconnect it from the drain port and use a brush on the wire to dislodge the buildup. You can use a new hose if the blockage is hard to reach.

7. Loose connection

Observe where the leaking is. If your portable ac leaks water from the connection between the drain port and hose, it indicates that the end of the drain hose is deformed or is not sealed to the drain spout.

How to fix it?

To hold the port and hose tightly together, you can take off the hose and then reattach it again.

You can cut off the deformed end and put the new end to the drain spout when it doesn’t work. Using a new hose is always a good option.

8. Broken pump

Normally, a portable ac drains the condensate by gravity. When it is not applicable, a pump is a solution to ensure the condensate can drain out of the hose smoothly.

There are two types of pumps: internal and external. Regardless of the type, the water will eventually remain in the tank and leak on the floor.

How to fix it?

For those using an external pump, you can choose to either replace it or repair it by a pro. For an internal pump, it is recommended to be repaired by a certified technician.

If you don’t bother to do that, another workaround is to change the placement to let the water drain by gravity.

9. Cracks and holes in your portable ac

Cracks and holes in your machine can occur for a variety of reasons, including overuse, low-quality materials, or an accident during transportation. If you just bought a brand-new device, it could be a manufacturing flaw.

How to fix it?

If the crack or hole is not substantial, you can try to patch-repair. Otherwise, asking a pro to replace the part can work better.

Sum up

This post has included a list of causes and solutions for portable ac leaking water.

You may have noticed that by committing to regular cleaning, you can avoid this issue to a large extent because dirty filters, evaporator coils, and drain hoses are the most common causes.

Tear and wear are also to blame. If you have an older model, this will happen more frequently. Buying a new one is sometimes a better option than spending the time and money to fix it.

Liz Yang is the founder of Airsmartly. She has been working at home for a few years and realizes that the performance of the HVAC system plays such an important role in our life. She has tested a lot of products in person, like humidifiers, air purifiers, dehumidifiers, and ACs, and wants to share tips about using or troubleshooting these products with you. Her uncle is an HVAC expert with over 30 years of experience in the field, and often offers assistance when she is unsure how to handle a situation. He is also in charge of reviewing the articles on this site.

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