Why Is My AC Unit Leaking Water?


Your air conditioning unit is one of the most significant contributors to indoor comfort. It keeps your indoor space cool during the hot summer months and ensures that your loved ones are comfortable. By design, your AC unit functions by drawing heat out of your indoor space and replacing it with cool air. The heat drawn from the inside is carried into the system where it forms a condensate or water. This is why you’ll always see the outdoor AC unit dripping water as it works.

Water, as a byproduct of the cooling process, is expected. However, certain problems can affect the exit channel where the water passes out, thus causing the ac unit to leak water. Water leaks in AC units can be a big issue, depending on how severe the problem is. Leaks can lead to safety and health problems like electric shocks, water damage, mold and mildew, etc.

If you’re experiencing similar problems, this article takes you through the common causes and fixes of water leaks in AC units.

Why You May Be Experiencing Water Leaks From Your AC

Blocked or Clogged Condensation Drain

One of the principal causes of water leaks in AC units is a blocked or clogged condensation drain. Your air conditioning unit is designed to extract heat from the air inside your home and carry it outside in the form of condensate or water. The water passed out of your AC unit drains into a pan located beneath the indoor coil on the unit. With continuous cooling action, water drains into the pan and moves out through the drain piping to avoid an overflow.

However, a clogged drain pipe may affect the water’s ability to drain out of the AC unit. This problem can cause water to collect, accumulate, and overflow from the pan. The overflow may be responsible for your ac unit leaking problem.

You need a professional HVAC contractor to diagnose and unclog the drainpipe to fix this problem. Calling on a professional HVAC contractor guarantees the problem will be addressed without causing additional damages that may require more money to fix. 

Dirty Air Filter

The air filter in your air conditioning unit should be cleaned or changed regularly. Air filters help to remove unwanted pathogens, lint, dust, and other microscopic materials that may affect your indoor air quality. However, they get clogged over time due to continuous filtering and may affect your AC’s performance. Dirty air filters affect ventilation which may cause the evaporator coils to freeze over. The thawed ice from the evaporator coils can cause excess water accumulation in the drain pan, which may cause water leaks.

Fix this problem by calling a professional HVAC contractor to remove and replace your AC air filters. This will improve your air conditioning unit’s efficiency, reduce energy costs, and improve your indoor air quality. 

Disconnected Drain Line

Although a rare occurrence, the leaking in your AC unit may be caused by a disconnected drain line. This problem may occur after a DIY repair or servicing without properly coupling the parts of your AC unit. It may also be caused when you’ve hired someone to work on the AC unit. In most cases, customers report this occurrence after swapping out their air filters.

Contact a professional HVAC contractor to diagnose and reconnect the drain line to fix this problem.

Faulty Condensate Pump

There are different types of air conditioning units on the market. Some units require a condensate pump to drain water from the system. This means that a faulty condensate pump will affect the unit’s ability to properly drain water which may cause water leaks.

Is your HVAC leaking water? Contact a professional to check whether the drain line isn’t clogged or disconnected. They should also check if the condensate pump is working correctly or not. You may suffer water leaks when either of these three problems occurs.
You may need to repair or replace your condensate pump to fix this problem.

Faulty Evaporator Coil

If you’re familiar with your AC’s condensation activities, you’re more likely to notice that it drips a large amount of water out of the unit when active. If the water volume changes and becomes thinner, the chances are high that you may be experiencing an undetected water leak.

If your AC unit has started to drip a small amount of water instead of a larger piddle, its evaporator coil may be broken or dirty. You can contact your HVAC contractor to take a look at this problem and repair it.

However, subscribing to an annual maintenance service is the best way to prevent and address this problem while saving money on ac repair. Through annual maintenance checks and servicing, your HVAC technicians can pick up the problem and help avoid or fix it. 

Low Refrigerant Level

A low refrigerant level may be responsible for your AC unit that isn’t cooling well or is leaking. The refrigerant level affects how your AC unit cools your home and a consistently low refrigerant level may cause your evaporator coils to freeze over, thus causing your evaporator pan to overflow and leak.

You can avoid this problem through air conditioning annual maintenance programs. HVAC contractors make sure to check your unit’s refrigerant level during maintenance services and refill it when necessary. 

Low Outdoor Temperature

Running your air conditioning unit during the winter months can cause water leaks. This is because your AC unit isn’t feeding on the hot or warm air that it has been designed for. Extracting cold air can cause the evaporator coils to freeze and thaw. The thawed ice increases the water level in the drain pan and can cause it to overflow. To avoid this problem, avoid using your AC unit when the temperature is 60-degrees Fahrenheit or below.  


No. Contact your HVAC contractor immediately once you notice a leaking AC unit to avoid water damage, as well as health and safety risks.
Contact your HVAC technician as quickly as possible. They’ll diagnose the problem and fix it.
Yes. Turn off your leaking AC and contact your trusted HVAC technician.

Whether you are encountering AC water leakage or any other HVAC problem, contact us now. We offer professional air conditioning services in San Fernando valley. Our technicians are ready to answer any questions you may have regarding your HVAC unit and address the issue immediately.

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