Why Is My Portable Air Conditioner Leaking Water?

Updated: Feb 15, 2024 5:14 PM


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.

Key Takeaways_

  • 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

Read our page on how to fix a portable air conditioner. 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.

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.

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.


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.

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

Nathan Rizzuti Avatar

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