Why Does My Window Air Conditioner Sound Like Running Water?

Jalin Coblentz
by Jalin Coblentz

Many people rely on window air conditioners to cool their homes if they don’t have a central air conditioner. Window air conditioners are smaller than other types of ACs, and they sometimes experience unique problems. One of these problems is when it sounds like there’s running water in your air conditioner.

While your air conditioner is running, it sucks the humidity out of the room it’s running in. The sound of running water in your air conditioner is the sound of condensation inside the air conditioner. This condensation then trickles to the bottom of your window air conditioner through pipes, where it’s then released outside your home.

It’s not unusual to hear the sound of running water in your window air conditioner. However, it can be concerning depending on what’s causing the noise. The most likely reason is humidity converted to condensation, but it’s not the only possibility. Let’s look at why your window air conditioner sounds like running water.

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Why Does My Window Air Conditioner Sound Like Running Water?

The most common reason that your window air conditioner sounds like running water is because of condensation. Your air conditioner does more than blow cold air into a room. It sucks the humidity out of it, similar to how a dehumidifier does. The moisture, however, has to go somewhere, or your air conditioner would flood and leak into your home.

Your air conditioner takes the humidity and converts it into condensation. The condensation is then either drained outside of your home or evaporates in the air conditioner, depending on the type of unit you have. Either way, the sound that you hear is condensation shifting around inside the air conditioner.

Running water in your air conditioner isn’t cause for concern or alarm unless it’s constant. Your air conditioner should be able to get rid of condensation on a steady basis before it has the chance to build up. If enough condensation builds up and starts to drip into your room, there’s a problem somewhere within your air conditioner.

Why Does My Window Air Conditioner Sound Like There’s Water in It?

If it sounds like there’s water inside your window air conditioner, that’s because there is. However, there should never be enough water in your air conditioner that it overflows into your home. There are two types of window air conditioners: those that drain condensation and those that evaporate it.

If your air conditioner evaporates condensation, you shouldn’t hear the constant sound of running water. In fact, you should rarely hear the water at all. The humidity that gets sucked into the air conditioner is immediately converted to evaporation within the AC. This evaporation is then used to help speed up the cooling process of your air conditioner.

Running water is more common if you have an AC that converts humidity to condensation and drains it out. This is because the condensation pools into a pan at the back of the air conditioner and drains out the bottom. Several drain pipes direct the water to the drain pan, which contributes to the sound of running water. However, if the sound is constant and persisting, there could be a blockage in the drain.

Is It Normal to Hear Water in Your Window Air Conditioner?

Hearing water in your window air conditioner is normal unless it’s a constant sound. There shouldn’t be a continuous water flow, but rather an occasional one. If you start to hear a persistent sound of water in your air conditioner, you likely have a drainage issue.

Another possible issue is that your air conditioner is tilted the wrong way. Window air conditioners that drain water are designed to operate only on gravity. They have to be tilted in a way that allows water at the bottom of the unit to freely flow to its backside, where it then exits the AC. If you hear the constant sound of running water in your window AC, it isn’t normal, and you should contact an HVAC professional.

How Do I Stop My Window Air Conditioner From Making Water Noises?

If the sound of running water in your air conditioner is constant, then you have a problem that needs fixing. Here are a few things to check out that you can do on your own.

Adjust the Tilt of the AC

Your window air conditioner doesn’t have a water pump inside of it that pushes the water out the back of it. The only way condensation can leave your AC is if it’s tilted the right way. Your window AC should be tilted backward so that the backside is lower than the front. This allows water to get to the drain pan and smoothly exit the air conditioner. You might have to put a small wedge underneath the front of the AC if it’s tilting the wrong way.

Remove the Drain Plug if Necessary

If the tilt of the AC is correct, but there’s still the sound of sloshing water, the drain may be plugged. Check the bottom of the outside of the unit to make sure that all the drain holes are open and free of plugs or other blockage.

Clean Out the Drain Pan

If the holes aren’t plugged, and the tilt is correct, the only remaining problem lies inside the drain pan. The more you use your window air conditioner, the more likely it is that residue and mildew have built up inside of it. If you can’t clean the drain pan from the outside, you’ll have to take the AC apart to access it.

Air Conditioner Sounds Like Water Dripping

If your window air conditioner has changed from the sound of running water to dripping, you’re too late. A drip inside your home indicates that your AC has flooded and water is starting to drip into your home.

Related Questions

Can I fix a dripping air conditioner myself?

Most dripping air conditioners are easily fixed by re-tilting the air conditioner or removing a drain plug. If you need to take your AC apart to clean the pan, however, you might need the help of an HVAC professional.

Is it expensive to fix my window air conditioner?

Most window air conditioner repairs are relatively cheap because the units are cheaper than central air. You can expect to pay $50 to $100 to repair an air conditioner with the sound of running water.

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Final Thoughts

Your window air conditioner will make several sounds during its operation. However, the sound of constant running water isn’t one that you want to hear. While the occasional sound of running water is merely condensation inside the unit, you shouldn’t hesitate to contact an HVAC professional if you’re worried. They have the tools and knowledge necessary to put your mind at ease.

Jalin Coblentz
Jalin Coblentz

Before I started writing, I worked for 6 plus years in the plumbing, electrical, and HVAC business. I was primarily an HVAC installer but also worked as a plumber and electrician. Now I'm a copywriter, focusing on home improvement content and guides.

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