Why Is My Portable Air Conditioner Leaking Water?

Updated: May 19, 2023 2:23 PM
why is my portable air conditioner leaking water

Forget about winter; summer is coming! Whether you live in a tropical area or a milder climate, being prepared to battle the heat is a must. Even the best air conditioners require maintenance to keep them in peak condition. All types of air conditioners, including portable units, can experience issues. So, if you’re wondering, “Why is my portable air conditioner leaking water?” keep reading.


  • Portable AC units with drain pans need to be emptied because many can’t drain on their own, like window units.
  • A water tank or drainage hose crack is the leading hardware issue causing portable AC unit leaks.
  • Low freon levels or dirty filters are also common issues that cause leakage.

Reasons a Portable Air Conditioner May Leak Water

From figuring out why the AC unit is blowing hot air to why it’s leaking, understanding your air conditioner is critical to keeping a house cool in the most cost-efficient way possible. Every air conditioner has to expel excess water drips from its evaporator coils. The most common way portable AC units address this issue is with a condensate drain pan that must be emptied by hand or a dedicated drain hose that drains out of a window. So, you’ll want to get started cleaning an AC drain line with vinegar, especially if your drain pan is dirty. If you are interested, you can learn more about how portable air coolers work.

If you find that your portable air conditioner is leaking, there are a few areas to check. Some of them are easy to fix, and others require more work. However, you must address the issue quickly because water leakage can lead to severe damage and costly repairs if left unchecked. So, if your AC sounds like running water, be sure to investigate the cause and fix it before it gets worse.

One of the greatest draws to portable AC units is how they can be set up almost anywhere. So for travelers, you may find our article on the best portable air conditioners for RVs interesting.

Insider Tip

Many portable AC units have room for an additional disposable filter in addition to their existing reusable filter. Adding the additional filter increases air quality and reduces the chances of leakage.

Cracked Drain Pan or Hose

The leading cause of portable AC leakage is drain hose or pan issues. When the drain pan becomes cracked, it can leak. Additionally, some units have a hose that runs outside, draining the pan automatically. If there is damage or a blockage in the hose, this also can cause water leaks. So be sure to check if the AC has water in the drain pan regularly to make sure to catch this before it becomes a big problem.

Another reason for leakage can be the freon. Using the wrong refrigerant can damage your system and cause refrigerant leaks, so you need to know what type of freon for a home air conditioner is best. And likewise, freon issues can be why a window air conditioner is freezing up.


Avoid putting your portable AC in an area with high humidity levels. High humidity increases condensation and the likelihood that the drain tray can overfill.

Broken Float Switch

Portable units with a condensate tray often feature a float switch (or drain plug). When the AC becomes full of water, the plug rises and triggers a switch that turns off the air conditioner unit, so the excess water doesn’t spill over. When the drain plug is broken, the tray overflows. To address this, remove the tray and ensure the plug is not damaged or stuck. You can avoid this issue if your unit has an auto-evaporation feature where it doesn’t collect water like the unit in our Honeywell portable air conditioner review.

STAT: Check the air filter on your portable AC at least every six weeks for maximum efficiency. (source)

For those interested in portable units, we’ve got a wide range of resources, such as our article exploring the best dual hose portable air conditioner.

Why Is My Portable Air Conditioner Leaking Water FAQs

How often do I need to drain my portable air conditioner?

Portable air conditioning units have a drip tray that fills fast because many have no drain line. When using your portable AC frequently, empty the drip tray every 6-8 hours.

What is the best way to store a portable air conditioner?

Make sure to empty the drain tube and drip pan of any excess water, letting them fully dry. Then store it in a dry area that doesn’t get below freezing during the winter.

Why is the portable AC filling with water so quickly?

The leading cause of a quick-filling water pan is placing a unit in an area with high humidity.

Nathan Rizzuti Avatar

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