Home Air Conditioner

Why is My AC Leaking Water? (11 Common Reasons and Picture of an AC)

Why is My AC Leaking Water? (11 Common Reasons and Picture of an AC)

Have you ever noticed water stains on your ceiling or walls? If so, there is a possibility that your air conditioner is leaking. Water leaks can be caused by various things and could eventually lead to more problems if left unattended.

To better understand how an AC unit works, here's an overview image of the AC unit itself:

How an AC Works - Possible reasons for an AC leak

In the AC unit, there is a series of tubes and components that are designed to circulate cold air throughout your home. These components work together to cool the air inside your home by removing heat from it. However, when these components get damaged or worn out over time, they can lead to water leaks in your system.

Water leaking is a serious problem in your AC unit and we highly recommend you consult and hire an HVAC professional to work on your unit.

Safety Caution: Do not try to fix AC, electricity, or refrigerant issues if you're not a certified professional. Always consult and hire an AC professional to fix your AC.

Disclaimer: This is not a DIY guide. Only for informational purposes. Always read your AC manual and follow AC professionals' advice.

Below are some common causes of an AC unit leaking water.

Common Reasons Why Your AC is Leaking Water

Drain line is clogged or broken

Drain Line is Broken

One of the most common causes of an AC unit leaking water is a clogged or broken drain line. This can happen due to excess debris, bending or kinking in the line itself, or even animal intrusion. If you suspect that your unit's drain line may be clogged, check for standing water around the outside of your unit.

Drain line is frozen

Drain Line is Frozen

In extreme weather conditions, the drain line can freeze and lead to a frozen AC unit. To prevent this from happening, you should keep your air conditioner covered when it's not in use during the colder months. You may also want to consider using an anti-freeze solution in your drain line to ensure that water doesn't build up in your unit.

AC Unit is not level

AC Unit is Not Level

Your air conditioner can leak water if it is not level. If you live in a home that has sloping floors or has settled unevenly, the unit could be misaligned, causing water to spill out of the seams on the outside of your unit. You should consult a professional technician to help adjust and fix your unit so that it doesn't leak anymore.

Insulation is broken

Insulation around the refrigerant lines can worn out or get holes. This can cause condensation water to appear on the pipes and potentially leak. The issue can be fixed by replacing the insulation that is broken or worn out; however, it may not be covered under your air conditioner's warranty.

Drain pan is boken

A drain pan, which is located inside the air conditioner unit, catches and stores excess condensation water. If it becomes cracked or rusted out, you will begin to notice a leak in your unit.

Drain pan is disconnected from the drain line

If the drain pan is disconnected from the drain line, it can no longer properly collect and dispose of excess water. The water leak will then come out from the inner AC unit, causing damage to the structure and possibly mold growth if not addressed.

Pan switch isn't working

Another common cause of an air conditioner leaking water is a faulty pan switch. The pan switch is designed to detect when your drain line becomes clogged or stops working, and will then shut off your unit so that it doesn't continue to leak water.

The condensation pump is broken

Some AC units include a condensate pump which is helpful when the AC unit is below ground level. This pump helps to pump excess water outside of your home, so if this pump stops working, you'll notice wet spots around your unit.

What if It's Leaking Refrigerant Instead of Water?

Are you sure that your AC is leaking water? It could also be leaking the refrigerant itself.

If you suspect it's a refrigerant leak, don't try to fix the issue yourself. Refrigerant is a chemical that should only be handled by HVAC professionals.

A refrigerant leak happens for a few reasons:

There's a hole in the evaporator coil

Cleaning evaporator coils should be done extremely carefully as they're incredibly fragile. If you do damage the evaporator coil, then it may cause a leak in your refrigerant lines.

There's a leak in the refrigerant lines

Refrigerant lines can break or crack due to natural wear and tear. They can also be connected poorly in the first place. This can cause a refrigerant leak in any part of the lines.

The expansion valve is broken

If the expansion valve is broken, it can cause your refrigerant to leak out from the AC unit. This can lead to a number of problems, including decreased cooling performance and higher utility bills.

The compressor is broken

The compressor is a key component of your air conditioner, and if it stops working properly or becomes damaged, it can cause the refrigerant to leak out.

How to Prevent an AC Leak in the Future?

Can you prevent an AC leak in the future? AC water or a refrigerant leak can happen to any one of us, but we surely can take some steps in order to prevent it from happening again. Here are some simple steps that can make a huge difference in the longevity of your AC unit:

Buy an AC with a pan switch

If you're about to buy a new AC, make sure it has the pan switch. The pan switch is a sensor that can detect water below the evaporator. If it does, the AC would turn off automatically to prevent water from damaging your unit.

Make sure your AC is made for cold weather

If you live in a cold place, you need to get an air conditioner that is suitable for your weather. Air conditioners made for warmer climates won't work well in the winter and might lead to frozen water pipes. Do your research on AC models before making any purchase.

Hire HVAC professional to install your AC

Do not install the AC yourself! It may sound like a plan but may turn out super-worse. It's better to hire an HVAC professional who can do it the right way with proper licenses. Installing an AC unit improperly could cause water damage and other problems. With an HVAC pro, you should also get a warranty for the installation.

Change filters frequently

Filters are the number one reason why your AC unit breaks fast. Many manufacturers advise changing the filter once a month or when it appears dirty, whichever comes first. Clogged filters will prevent air to circulate in the indoor unit which could lead to a multiple issues from overheating to water leaks.

Clean off the dust from evaporator coils

The evaporator coils are in the indoor unit and can collect a lot of dirt and dust that can prevent heat transfer. It's important to clean this off regularly and make sure you're using tools and chemicals supported by your AC seller. Remember that evaporator coils are sensitive and you should use extra care when handling them.


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