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 drain tank that needs to be emptied every so often.
  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 Is Leaking Water Out of Drain Spout

The most common culprit of water leaking out of a portable air conditioner is the drain spout located on the back of the unit.

Under normal circumstances, the moisture accumulated inside your portable air conditioning unit is collected in its drain pan and removed via the drain spout.

However, if the drain spout is compromised – be it from damage or improper fitting – water can start to leak out, often leading to puddles on your floor.

Why Does Water Leak Out of the Portable AC’s Drain Spout?

There are two common reasons why a drain spout might start causing condensate leakage problems:

  1. Damage: Over time, the drain spout may get worn out or damaged, leading to leaks. The spout may develop cracks or splits, allowing water to escape – even when the drain spout cap is properly screwed on.
  2. Improper Installation: If the spout isn’t attached properly to the air conditioning unit, it can cause water to leak out. This is often due to the spout not being securely tightened or being misaligned.

What Should You Do if You Have a Leaky Portable AC Drain Spout?

First, check your air conditioner’s drain spout for any signs of damage.

If you see water leaking out of the drain spout, try to identify where the water is coming from. Is it seeping out from the rubber seal? If it’s the rubber seal, you’ll need to replace it if it’s damaged – or find something you can use to seal the spout to stop the flow.

For improperly installed spouts, ensure that it is fitted correctly and securely. It might be beneficial to consult the unit’s user manual or contact the manufacturer for specific installation instructions to avoid potential damage or improper fitting.

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:

Check If the Drain Hose Is Clogged

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.

Check If the Drain Hose Is Sealed to the Drain Spout

Another thing to check is if the drain 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.

13 thoughts on “What to Do When Your Portable Air Conditioner Is Leaking Water”

  1. I have brand new port 10.000 btu cool living air condition and heater after it runs about ten minutes water is on floor I should not have to drain this every ten minutes do you know what is wrong

    • Hi Gwendolyn,

      The first thing to check is if the drain port cap is on. Most portable ACs have at least 1 (some have 2) drain ports on the back of them. Make sure that the cap is on and rubber seal is preventing the port from leaking.

      Another thing to check is if the drain pan or drain tank is cracked. You might need to disassemble the AC to check on that. The drain pan/tank is where the condensate is supposed to collect in a portable AC. If the pan/tank is cracked, then water will leak out.

      Also, make sure that your portable AC is on a level surface when using it. If its on an incline, water may leak out.

      Best of luck,

      • OMG Trey!

        Wow. My portable unit leaking from being on an incline. I did not know how the inside was set up until your article. Thank you! Of course, it is leaking from not being straight but if one does not know how it works then it never enter my mind that the unit needs to be completely flat. So this is important for anyone in an RV using a portable unit as parking on an incline will also be tilting your portable unit! lol I also titled unit so it was hitting me directly in my face. So it leaked everywhere and I was trying to determine cause. It was merely it needs to be flat. lol

  2. I used my Portable air conditioner 2 times. It leaked. No worries with m y window air conditioner. A year ago I had the floor model. It leaked and stained my ceiling.it was in my upstairs bedroom.leaked into my living room. My son took it. Stupid me bought another one. I thought the. Other one may of been a fluke.i put this one in a huge toat It’s good thing I did because it leaked.it was on ac Not deumidafier. $200. I paid. I don’t recommend buying one.

    • Hi Crystal,

      The most common reason for a portable AC to leak water is a loose or leaky drain plug. The rubber seal on those plugs can get damaged or crack over time, so I recommend checking that to see if that’s where the water is leaking out from

      Hope this helps,

  3. I have a floor model ac unit that is starting to spit water out the vent where the cold air blows. What could be the cause and how do I stop it? I have cleaned both the filters on the back. Didn’t have this problem last year.

    • Hi Becki,

      The most common cause for a portable AC spitting water out is a full condensate tank. Try emptying the condensate collection tank from the drain spout on the back of the unit.

      Portable ACs can also spit water out if the evaporator coil is old and corroded. Water will stick to the coil and and get blown out instead of dripping down.

      However, sometimes, just plain high humidity levels will cause a portable AC to spit water out – the problem usually resolves itself when the AC brings humidity back down to normal levels.

      Hope this helps,

  4. Hello Trey. My 3 year old Danby MODEL DPA120BCCWDB condensing portable air conditioner started leaking from the back of the unit. It never did before, regardless of the humidity levels. I removed the back cover and started the unit to confirm the condenser coil motor was still spinning.

    That’s when I noticed a crack at the bottom of the condenser metal side panel, just above the evaporator fan. The splashed water was leaking through the crack in the side of the condenser coil assembly, splashing against the back of the outside cover and dripped onto the floor as evidenced by the slight witness mark on the rear AC cover panel.

    This is a link to my picture of the source of the leak: https://photos.app.goo.gl/cYwyRkPnqXLDcNcy5

    I bought a $8.00 stick of high temperature, drillable automotive 2 part epoxy putty, mixed a small amount, sanded the condenser area and covered the hole.

    One hour later, fully cured, it looks like a black dried wad of chewing gum, hard as a rock. I reinstalled the rear cover, problem solved.

    I had not read about this problem anywhere else online. Maybe we can save somebody’s AC unit from the going to the trash for such a simple cheap repair.

  5. Hi
    I have a portable AC unit that normally displaces condensation through the exhaust hose. No water collects.
    The AC coils froze up last week for some reason. Perhaps because it was so hot and humid. I unplugged it and let the ice melt. It still cools ok but now throws off 1-2 gallons of water every 12 hours. Time for a new unit perhaps ?

    • Hi Gary,

      I’m wondering if your portable AC has a refrigerant leak. If so, soon it might stop cooling altogether. Then your options will to either bring it to an appliance repair shop to repair the leak an recharge the unit, or dispose of the unit and get a new one.


  6. I found a crack in the plastic (bottom part) of my Delonghi portable a/c unit…
    so consequently water is dripping out of that (no issues with the drip spout or anything)…. just a pool of water due to the crack….
    is this something I can glue together or silicone??


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