Why Does My Portable AC Fill With Water Quickly? (10 Causes)

If your portable air conditioner fills with water quickly, you’re not alone. It can be frustrating and potentially costly, especially if you aren’t sure what to do when this happens. Read on to learn more about this situation and the steps needed to troubleshoot and deal with any problem.

Why Does My Portable AC Fill With Water Quickly? (10 Possible Causes)

As with other issues that ACs can sometimes experience, there are many reasons why a portable AC could fill with water. If your AC is filling with water too quickly, review these typical causes to determine which one is causing your problem.

Portable AC Fills with Water Quickly

1. Dirty Air Filter

Air must move through the air filters unobstructed to remove excess moisture and cool the air. If your air filters are blocked or dirty, your portable air conditioner will fill up much faster with water. Therefore, check your air filters often to ensure they are clean and in good condition.

2. First Time Cooling Or A New Equipment

Sometimes a new unit or an older unit in a new space might collect water much faster than expected. This is normal and does not mean something is wrong with your new portable AC. After it runs for a little longer, the problem will usually resolve itself. If not, check out our other tips for fixing your AC.

3. Faulty Condensate Pump

A condensate pump collects excess water from the portable AC. If your AC is filling with water, then there might be something wrong with your condensate pump. Not all units have a condensate pump, but it’s always a good idea to hire a repair specialist if you have a faulty one.

4. Faulty Float Operation

The float operation is a mechanism in your portable AC that turns off the unit if the water reaches too high of a level. It’s designed to kick in if other issues with your AC lead to a rapid increase in water. If your AC is filling with water quickly and not turning off or is overflowing, you might have a faulty float operation in your unit.

5. Blocked Water Tank and Drain Hose

If your water tank and drain hose are clogged, you’ll notice the AC fills with water much faster than anticipated. If you’re using a drain hose, you shouldn’t have any water in the tank at all. Check your drain hose for dirt, especially in the areas where it turns. Any blockage in the hose can be the source of your problem.

6. Malfunctioning Water Level Indicator

The water level indicator tracks the level in the water tank of your unit. Once it hits a certain point, it should trigger your water pump or other drainage systems to kick in. If the indicator is malfunctioning and not alerting the drainage system, the tank could be filling past the appropriate level. Once the indicator is repaired, your system should work properly again.

7. Defective Portable AC Blower Fan

Your AC blower fan is crucial to the proper running of your unit. If your blower fan is defective, it can result in water freezing in your unit’s evaporator coils. Frost or ice in the evaporator coils can drip into the water pan, leading to water in the pan filling up too fast.

8. Clogged Evaporator Coils

When your AC runs, it expels air through the evaporator coils. Unfortunately, the coils can become clogged with dirt or frosted over due to issues with the unit (see the previous section). When this happens, it will continue to drip into the water pan, filling your AC quicker than ideal.

9. Less Condensate Pan Capacity

If you feel as though you are emptying your condensate pan (water tray) too often, the tray might just be too small for the unit. Smaller pans fill up much faster than larger pans, so a smaller pan means you will need to empty it more often. If this is the case for your unit, you can look into other mechanisms to help resolve the issue, such as a drain hose or condensate pump.

10. High Humidity In Your Area

High humidity can cause your portable AC to fill with water as it works extra hard to remove it from the air. If the humidity level is too high for your unit to handle, this will most likely cause your portable AC to fail cooling your space. To help counter this, add a dehumidifier to the room during periods of high humidity, which will also aid in removing moisture from the air.

How To Fix Portable AC Filling Up With Water So Quickly (Easy DIY Steps)

You can stop your portable AC from filling up with water in a few easy steps.

  1. Clean the air filters
  2. Clean the drain hose
  3. Clean the drain tank
  4. Run a dehumidifier in the space
Filter Needs Cleaning

Cleaning the filters, drain hose, and drain tank will help you clear any potential blockages causing your AC to fill with water fast. To clean the unit, you will need a screwdriver, a damp cloth, and a bucket. You might also want to have a new air filter handy if yours needs to be changed.

Once you have your tools, follow these steps to clean your unit:

  1. Unplug your unit and place it on a flat surface
  2. Drain the water from your unit
  3. Follow your filter’s instructions to clean it. Some filters are removable. These can be cleaned easily with a vacuum and a soak in warm soapy water. Make sure to allow your filter to completely dry after soaking it before you put it back into your portable air conditioner.
  4. Use a damp cloth to wipe down the coils and remove debris (very carefully)
  5. Inspect the drain hose and tank and carefully remove any debris or blockages with your damp cloth.

Running a dehumidifier will solve the problem if high humidity is the culprit. If you clean the filters, hose, and tank but still have an issue with the water filling too quickly, this might solve your problem.

What Will Happen If The Portable AC Is Full of Water?

Leaving your portable AC full of water can negatively affect your unit. These are the most common results of not draining your AC:

  • Air conditioner will turn off until the water is emptied
  • Condensate pan will overflow, spilling water all over the floor
  • Mold and mildew will grow inside your unit

These are all bad for your unit, so you want to resolve any issues with your unit filling with water sooner rather than later. The longer you allow water to collect in your unit, the worse it will be. With that in mind, the best thing you can do is empty the water and resolve whichever issues are causing it to fill so quickly.

Common Portable AC Brands Continue Filling With Water

Unfortunately, some AC brands are known for filling with water. If you have one of these brands, it’s essential to be aware of this issue and how to resolve it. You might not find these problems in the user manual, but that doesn’t mean you cannot fix them.


Luckily, LG units filling with water too quickly is something you can easily resolve by yourself. Often, the problem is with the drain hose. Cleaning the hoses or setting up a continuous drain can help solve the problem for you. LG has uploaded a number of videos via YouTube that step-by-step the common causes of portable ACs filling with water and the fixes that can remedy the issue.


Delonghi is another brand that is known for continually filling with water. They often turn off and blink the TF error message that means the tank is full. We recommend running the troubleshooting tips outlined above in this article to resolve the issue.

DeLonghi Portable AC

People Also Ask (FAQ)

Do portable air conditioners need water?

Standard portable air conditioners do not require you to add water. However, some portable air conditioners are evaporative or “swamp coolers”. If you have one of these, you will need to add ice and water.

Swamp coolers cool your space by evaporating the water in the unit.

Where does the water go in a portable air conditioner?

If you have a portable air conditioner that requires you to add water, you will add the water to the reservoir. You should also add ice to the reservoir while you do this. You can find out exactly where the reservoir is in your unit by looking at your user’s manual.

In air conditioners that don’t require water, water will be removed from the air and stored either in a condensation bin or moved out through a drainage hose.

Is overflowing water dangerous around a portable ac unit?

Most of the time, overflowing water around your portable AC is not going to pose an immediate danger to you and your family. Regardless, you should still clean it up and fix your unit as soon as you can. The longer the water sits, the more likely it is that mold and mildew will develop, which can be a threat to your health.


Portable AC units often fill with water too quickly. If this is happening to you, you can often address the problem on your own by following the steps we outlined in this article. By troubleshooting the causes we described, you’ll be able to determine the problem and fix your unit faster.

Josh Mitchell

Josh Mitchell

My name is Josh and I am obsessed with DIY and improving my family home. HVAC topics can be tricky for homeowners so I decided to share my knowledge on the subject. When I am not working on DIY projects, you can find me at the beach or my local coffee shop.