What to Do When Your Portable Air Conditioner Is Leaking Water

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When it’s hot outside, portable air conditioners can be a great choice to cool an area of your home. But like many other appliances, portable air conditioners need routine maintenance to function.

A secondary function of air conditioners is to dehumidify the air. When a portable air conditioner dehumidifies, it removes moisture from the air. But that moisture needs to go somewhere.

Sometimes, your portable air conditioner will malfunction and leak water all over your floor. In this article, I’ll discuss what you need to do when your portable air conditioner is leaking water.

Portable air conditioner drainage types

If your portable air conditioner is leaking water, the first thing to figure out is where the water is coming from.

There are three main types of air conditioner drainage methods:

  1. Condensate tank. In this method, your portable AC will remove moisture from the air and put it in an internal tank that needs to be emptied.

  2. Evaporation through the air exhaust hose. In this method, your portable AC will evaporate the condensation that it collects. It is ejected from the unit to the outside via the exhaust hose. An air conditioner that utilizes this method will also have a condensate tank. The tank is needed to collect any extra moisture that it cannot immediately evaporate.

  3. Drainage hose. In this method, your portable AC will remove the condensation via a hose attached to the drain spout. This method allows for the continuous removal of moisture from the AC unit, so you won’t need to empty the condensate tank.

Portable AC with condensate tank is leaking

No matter what kind of portable AC you have, it likely has a condensate collection tank. The condensate collection tank serves to collect moisture that is removed from the air.

Even if your portable AC is set up to continuously drain moisture, it will still use a collection tank when extra moisture is produced. For this reason, it is always important to take a look at the condensate tank when your portable AC is leaking.

Condensate tank or drain pan is cracked

If your portable AC collects condensate in a tank within the unit, then any crack or damage will cause the tank the leak. 

To find out if the condensate tank is cracked, first, empty the tank:

  1. Shut off and unplug the AC.

  2. Put the AC on an elevated surface such as a stool.

  3. Orient the AC so the drain spout hangs over the edge of the surface.

  4. Place a plastic container under the drain spout. Ensure the container is large enough to hold at least 1 liter of water.

  5. Remove the drain spout cap and allow all the water to drain out.

  6. When the water finishes draining, replace the drain cap.
Water draining from portable AC condensate tank
Emptying the condensate tank on a portable air conditioner

After you empty the condensate tank, return the AC to its operating location and plug it back in. Turn on your AC and set it to “Cool” mode. As the AC runs, it will dehumidify the air and condensate will collect in its tank. If you notice that water is still leaking from its tank, then the condensate tank is cracked.

Condensate tanks are not typically user-serviceable. However, if you’re able to pinpoint the location of the leak you may be able to take apart the unit and repair the tank. Consult your owner’s manual for more information.

Portable AC condensate tank is clogged

If your portable AC’s condensate drain tank or pan is clogged, it will leak water.

The condensate drain tank and pan collect water from the portable AC’s condensate. The condensate drips off of the AC’s cooling coil as a byproduct of the cooling process.

Clean out the sludge and grime from your portable AC’s drain tank or drain pan to prevent it from leaking water.

portable ac dirty drain pan

Portable AC float switch is not working

The float switch is a device that detects when the condensate tank is full. When the water level in the condensate tank reaches a certain level, the float switch triggers and disables the air conditioner.

If the float switch is broken, then it will not trigger an alarm to shut off your AC when the condensate tank is full. Your air conditioner will continue to run, and water will overflow out of the condensate tank.

Like most parts in portable ACs, the float switch is not designed to be user-serviceable.

However, some float switches can be fixed by cleaning them out.

portable ac float switch

If you have a broken float switch, here are your options:

  • Keep an eye on the condensate level and empty the tank when necessary.

  • Get a new portable air conditioner.

  • Install a drain hose to continuously remove water from the unit.

Portable AC with hose drain is leaking

On some portable air conditioners, you can install a drain hose. Water is drained out of the unit from the drain hose. The end of the hose is directed outside, where water drips out of it.

One of the advantages of using a dedicated drain hose is that you won’t need to worry about emptying the condensate tank. This is very advantageous, especially if you live in a humid area where you need to empty the condensate tank multiple times a day.

If your portable AC with a drain hose is leaking, there are a few different things that you can check:

  • The first thing to check is if the drain hose is clogged. When the drain hose is clogged, water won’t be able to drain out and it will accumulate in the AC.

    A common source of clogs is sludge or slime build-up in the hose. To prevent slime build-up, you will need to perform some routine maintenance on your AC drain hose.

    Once a month, remove the hose and pour some bleach through the hose. The bleach will kill any organic matter and help prevent any future growth.

  • Another thing to check is if the hose is sealed to the drain spout. Take a look at where the hose connects to the drain spout and see if it is leaking there.

    Sometimes, the hose can become deformed or cracked. If the hose is long enough, you can cut off the cracked section and re-attach the hose to the drain spout.

    You can use a zip-tie to secure the drain hose to the drain spout, but check with your owner’s manual to confirm the proper method.

Portable AC condensate pump is broken

Sometimes, it is not possible to utilize gravity to drain the condensate with a hose. If the drain line is directed upwards, the condensate won’t be able to drain. In this case, a condensate pump is required to move the condensate through the drain line.

If the condensate pump malfunctions, then water will build up in your portable AC and leak out. In this case, you’ll need to repair or replace the condensate pump.

Some portable air conditioners have built-in condensate pumps. Check with your owner’s manual to see if there are any repair or replacement instructions. They may or may not be user-serviceable.

Hi, my name is Trey Lewis and I’m the founder and chief editor at HVAC Training Shop. My goal for this website is to help homeowners troubleshoot and maintain their home’s HVAC systems. Whether it’s changing an air filter, troubleshooting a blower motor, or just buying a new humidifier, I want to make sure that you’re covered.

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