Why Is My AC Leaking Water? A Portland Tech Explains

First of all, if your inside AC unit is leaking water in your Portland home, you need to shut off your thermostat ASAP to prevent water damage.

Now that you’ve turned off your AC, you’re probably wondering why your system is leaking water.

Part of your AC’s job is to dehumidify your home, so it’s normal for your AC system to collect water. However, it’s not normal for your AC to leak that water into your home. If your AC is leaking, you’re likely dealing with:

  • A clogged air filter
  • A cracked drain pan
  • A clogged condensate drain line
  • A low refrigerant level

Let’s dive into how your AC collects water when it dehumidifies your home, how the above issues cause leaks and what you can do to stop the leakage.


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How your AC collects water

As we mentioned above, your AC not only cools your home, it dehumidifies it as well. Here’s how:

  1. AC pulls in warm air from your home
  2. The warm air passes over a cold evaporator coil and moisture from the air condenses on the coil, forming water droplets
  3. This condensation drips into a drain pan and exits your home through a condensate drain line

However, if you are experiencing any of the AC system issues we listed above, you may see water puddling around your AC unit.

Issue #1: Clogged air filter

Since your AC filter prevents debris and particles from entering your system, it can clog over time. Once it clogs, your AC system will have a hard time pulling air into your AC system.

If there isn’t enough warm air blowing over the evaporator coils, they will freeze. This is because they are full of a very cold substance called refrigerant.

After the ice melts, the drain pan can overflow and a puddle can form around your AC’s base.

Luckily, if a clogged air filter is your issue, the fix is easy:

  1. Turn off your AC
  2. Replace your air filter if it looks like the filter on the right. Note: To prevent clogs, you should replace your air filter every 1-2 months.
Clean air filter versus clogged air filter

Clean vs cloged air filter

  1. Wait for the ice on the coil to melt
  2. Turn your AC back on

If changing out your filter doesn’t stop your AC from leaking water, continue reading.

Issue #2: Cracked drain pan

As we talked about above, the drain pan catches the condensation dripping off of the evaporator coil. Because the drain pan is constantly wet, over time it can rust and crack, which can cause it to leak.

To fix a cracked drain pan, you will want to call a professional. Because the drain pan sits directly underneath the evaporator coil, you could cause damage to your AC system if you try to replace it yourself.

Issue #3: Clogged condensate drain line

If you’ve noticed that your AC has automatically shut off, you could have a clogged condensate drain line. Most AC systems will turn off once they detect a clog in the drain line to prevent more water from leaking.

In order to unclog the drain line, you will need a wet/dry vacuum to do the following:

  1. Look for the end of the drain line. It’s usually a thin PVC pipe attached to a wall next to your outdoor AC unit.
  1. Seal your vacuum hose mouth onto the end of the line with either duct tape or a towel
  2. Turn on the vacuum for 3 minutes

If vacuuming doesn’t clear out your drain line, you’re probably dealing with a major clog high-up in the drain line. In this case, you want to call a professional to avoid risking major damage to your AC system.

Issue #4: Low refrigerant levels

If you see water around your AC and hear hissing sounds coming from your AC, you probably have low refrigerant levels. Refrigerant flows in a closed-loop system, so if your refrigerant levels are low, it’s because of a leak.

So, how do low refrigerant levels cause an AC to leak?

Well, refrigerant is a cold liquid agent in the evaporator coil that absorbs heat from your home and dumps the heat outside.

When refrigerant levels decrease, the condensation on the evaporator coil will end up freezing because your AC can’t absorb heat as well. After the ice melts, water will leak.

To fix a refrigerant leak, you will want to call an HVAC professional. Refrigerant is toxic, and a technician will have the equipment and skills necessary to properly seal the leak and refill the refrigerant to the right levels.

Want a high-quality & easy AC repair? Contact Four Seasons

Our Portland technicians are highly skilled and can repair all AC brands and models. On top of quality, we provide easy 2-hour appointment slots and same-day service.

Schedule an appointment today!