Air Conditioner Sounds Like Running Water (Cause & Solution)

You don’t want to be without cool air during the hot summer months, so if your air conditioner sounds like water dripping, you want to know the cause as soon as possible. Letting this issue persist can lead to major issues, so catching it early is key.

Why Does My Air Conditioner Sound Like Running Water? (Common Causes)

If your air conditioner sounds like water dripping, it might be due to one of these common causes.

Central AC Unit Between Backdoor Stairs and Wood Planked Wall

Clogged Condensate Drain Line

When you hear your air conditioner making a water noise, the first thing to check is the condensate drain line. This issue is the most common because dust can build up and block the flow. A drain line that stays clogged can cause leaks or even make your unit shut off completely.

Cracked Drain Pan

Over time, the drain pan can rust and crack. You might wonder, “Why does my AC sound like running water?” without realizing your drain pan is leaking. For drain pans with severe damage, you should call an HVAC professional. They can replace the pan and check the surrounding area and the unit itself to ensure everything is in good shape.

Improper Installation Or Size Of The Unit

When you hear AC sounds like running water, it might be due to the wrong sized unit. Undersized AC units have to work harder to cool a house, which causes it to wear out quickly. If your AC struggles to cool your whole house, call an HVAC professional to assess the unit.

Broken Condensate Pump

Running your air conditioner with a broken condensate pump can lead to expensive repairs. First, you can check your pump to see if the float is stuck. If so, freeing it is a quick fix. However, with a cracked float, you’ll need to call a professional to replace the float and possibly the entire pump.

Dirty Air Filter

You might think, “My AC sounds like running water — that’s not an air filter problem.” However, a dirty air filter can prevent air from reaching the evaporator coil. The lack of air makes the coil freeze, and when the ice melts, it overflows from the drain pan.

Lack Of Refrigerant

AC units require a certain amount and type of refrigerant. If your unit doesn’t have enough, it could be due to a leak in the compressor line. A lack of refrigerant causes the evaporator coils to freeze and can damage the compressor itself. Call a professional to help with this problem, as adding too much refrigerant can also cause problems.

Types Of Water Sounds Coming From AC Unit

Various types of water sounds can come from your AC unit. Each sound has a different cause.

Running Water

If your central air conditioner sounds like water running, the condensation isn’t draining. Moisture builds up in your AC unit naturally, but when the unit functions properly, this moisture drains.

Hearing dripping or running water can also mean that humidity is backing up in your ductwork or you have a refrigerant leak. These issues call for an HVAC professional, so don’t wait to call for a service checkup. It’s best to turn your AC off completely until you can find a proper diagnosis.

Bubbling Water

AC units producing a bubbling or gurgling noise have a pressure problem. Too much refrigerant in your unit could throw off the internal pressure. A refrigerant leak will also cause this noise. Checking and maintaining the proper refrigerant level is crucial to keeping your air conditioner in top condition.

This noise means different things for a central AC unit compared to a window unit. If you find that your window air conditioner makes a gurgling noise, the issue relates to a cracked or clogged drain line.

How To Fix The Running Water Sound In AC Units?

There are a few DIY solutions to fix the running water sound in your AC unit.

You can fix a clogged condensate drain line yourself. Turn off your AC unit and check for debris in the drain line. Carefully remove anything you see so it won’t get pushed further into the pipe. Pour in a cup of white vinegar and wait 30 minutes to turn your air conditioner back on.

You can repair cracked drain pans using a sealant. Check the area around the pan to ensure no mold has grown. You should also be certain that the leak hasn’t rotted the floor or walls around the drain pan.

In the case of a dirty filter, you can vacuum off the dust or replace it yourself.

Carrier Technician

People Also Ask (FAQ)

Here is a list of frequently asked questions on AC noises.

How much does it cost to fix an AC that sounds like running water?

Repair costs vary according to the root of the problem, but the price can run anywhere from $150 to $650. Contacting a professional for repairs is more affordable than having to replace the entire unit, though, so don’t hesitate to contact your HVAC company.

How long does it take to fix the AC with water sounds?

Water sounds are a common problem with AC units, so professionals know exactly what to do. It won’t take them long to repair or replace the source of the issue. It’s worth noting that if your window air conditioner sounds like water, it’s usually best to replace the whole unit instead of paying for repairs.

How can you prevent your AC from sounding like running water?

Regular maintenance will prevent running water sounds from coming from your AC unit. You should have a professional come every six months or year. You can do minor maintenance yourself, such as checking your filter every three months.

How do I drain the condensate from my house AC?

Keep your condensate line clean using the vinegar method above. For clogs, you can use a wet vac to remove the debris. If your window AC sounds like water, you can try to change the tilt, so it drains outside of the house.


If you’re wondering, “Why does my AC unit sound like water?” you most likely need to call your HVAC service. There are a few issues you can fix on your own, but you want to ensure nothing will cause major, expensive damage to your compressor.

Josh Mitchell

Josh Mitchell

My name is Josh and I am obsessed with DIY and improving my family home. HVAC topics can be tricky for homeowners so I decided to share my knowledge on the subject. When I am not working on DIY projects, you can find me at the beach or my local coffee shop.