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Why Is My Portable AC Producing So Much Water

Why Is My Portable AC Producing So Much Water? It Fills Up Too Quickly!

For many people, the most significant disadvantage of using a portable air conditioner is the need to empty the bucket. However, thanks to technological advancements, most models these days are self-evaporative, at least partially, which means you don’t have to drain it as frequently as before.

If your portable AC produces too much water, it could indicate that something is wrong with your appliance. A dirty filter, clogged drain hose, or faulty condensate pump are usually to blame. However, high humidity could also be the culprit.

There are more reasons for this issue. I will walk you through all the common causes and solutions in more detail in this post. Let’s get started right away!

1. High humidity in the house


If you notice your portable air conditioner filling up faster than usual, check the numbers on the hygrometer. The relative humidity in your home is probably quite high, around 70% or 75%.

Since indoor humidity is highly correlated with outdoor humidity, the humid climate in your area may be on its way.

Apart from that, your daily activities can contribute to an increase in indoor humidity. For example, have you recently begun to cook at home? Have you recently relocated your portable air conditioner near the bathroom?

When more water vapor lingers in the air, your portable AC will produce much more water, even if it has a self-evaporation feature. That’s why you will see it keeps filling with water.

What to do?

To be honest, you have little control over the weather outside. However, there are some methods for reducing indoor humidity.

You could try running a dehumidifier alongside your air conditioner. While you may need to drain the water in your dehumidifier, it can reduce the strain on your portable AC, which is still helpful. 

Alternatively, after showing and cooking, you can run an exhaust fan to expel more water from your home.

2. Dirty air filter 

Portable air conditioners, like any other type of air conditioner, include an air filter to filter out contaminants in the air. It can become clogged over time if there is too much dust and dirt in it, resulting in reduced airflow.

When there isn’t enough air to warm up the evaporator coil, it will freeze, and the thawed ice will drip into the condensate pan, quickly filling the water bucket.

What to do?

Luckily, this problem is easy to address. Most portable AC air filters are reusable. You can take it out, rinse it with running water, and use a brush to get rid of the stubborn buildup and stain. Before putting it back, please make sure it is completely dry.

3. Filthy evaporator coil

Not only a dirty air filter but also a filthy evaporator coil can get the coil to freeze up and produce a lot of water in a short time. 

A portion of dust and dirt will enter the inside of the AC, even though the filter works, then some impurities will land on the evaporator coil, impeding the heating transfer process. 

What to do?

You can solve this problem by cleaning the coil. If you decide to do it yourself, you must first disassemble the machine to gain access to the coil. There are specific coil cleaners on the market.

If you don’t bother to do it, you can make a call to an HVAC expert.

4. Faulty blower fan

As previously stated, a lack of airflow can result in more water in the water tank. Aside from the air filter, another component that can significantly affect airflow is the blower fan.

When it fails, it loses the ability to draw enough air into your portable AC, causing your AC to produce more water.

What to do?

A faulty blower fan can be caused by a variety of factors, including low lubricant levels, mechanical tear and wear, and bent fan blades. If you lack the necessary knowledge, you should hire a certified technician to locate the problem and determine whether it requires repair or replacement.

5. Damaged float switch

A float switch is a little gadget that can turn off the air conditioner when the drip pan is full. When it is faulty, it can cause your portable AC either to leak or to turn off when the water tank has not filled up with water yet.

When the latter happens, you will need to dump the water much more often than usual. You’ll be perplexed as to why your air conditioner fills up so quickly, but the drain pan is not full when you open it.

What to do?

It is likely that the float switch is clogged by the grime and debris accumulated in it over time. In this case, you can access it and clean it off with a soft cloth. 

Otherwise, you may need to replace it with a new switch. It is inexpensive.

6. Clogged drain hose

Since the majority of models these days are self-evaporative, making draining water through the bucket is adequate. But if your portable ac utilizes other draining methods, like draining through the hose or condensate pump, you will have to deal with the issues that these additional accessories bring.

When the drain hose or hole becomes clogged, the water from your air conditioner backs up and fills the tray. It will make you wonder why your portable air conditioner keeps filling up despite being connected to a hose.

What to do?

You need to take apart the hose and then dislodge the slime in the hose with a tube brush. Adding some vinegar or bleach to the tube is helpful in preventing the growth of buildup in the future.

7. Faulty condensate pump 

When your portable AC can’t drain through the hose via gravity, you should use a condensate pump. Some models include one, while others must be connected to an external one. 

When the condensate pump is defective, the water will back up as well, leading to your unit filling up with water quickly.

What to do?

For the external pump, you can clean it off to see if the problem is mitigated. If not, you can purchase a new one for a reasonable price.

A technician may be required to repair the built-in pump.

8. You just got a brand-new appliance

Portable air conditioners can remove excess water in the air. That’s why many of my friends like to use their portable ACs as a dehumidifier, even though it is not so effective.

Similar to running a new dehumidifier, your new portable AC has a high likelihood of producing more water at the beginning. This is because it will draw moisture from the wooden furniture, wall, or floor, assuming the room hasn’t been airconditioned for a while.

What to do?

There is nothing you should do. Your situation will improve in a few days.


Fixing a portable AC that keeps filling with water is usually not rocket science.

If it is not caused by the high indoor humidity, a dirty air filter or evaporator coil is often the culprit. When a thorough cleaning doesn’t work, you may need to inspect the blower fan.

Hopefully, this post has addressed your situation, and you are able to deal with a portable AC that is producing too much water.

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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 more than 150 products in person, including 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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