Why is Water Leaking From My Air Conditioner?

Have you ever walked by your air conditioner and noticed that it’s leaking water? What about taken a look at it and noticed that there’s a stream of small droplets coming out of your system? While this causes a lot of homeowners to panic and think something has gone catastrophically wrong with their air conditioner, the truth is there’s no need to overreact. Water coming from your air conditioner is actually extremely normal, as water is a natural byproduct of the air conditioning process removing humidity from the air.

On this blog we’ll explain what causes water to form in your air conditioner and why it’s not nearly as serious of a problem as you might think.


So why is there water in your air conditioner in the first place? Does your air conditioner run on water for some reason? Well, yes and no—yes in that water is an important part of the cooling process, not in the way that your air conditioner needs to be connected to a water supply. You see, the water supply for your air conditioner is actually located all around you: in the air in your home. Air is not pure oxygen—it contains other gasses like nitrogen as well as evaporated water or water vapor.

When water vapor reaches a certain temperature, the vapor then condenses back into liquid through a process called “condensation.” You can see this principle in action right in your own home: simply make a glass of ice water and leave it on a table. After just a few short minutes, you should start seeing a thin layer of water forming on the outside of the glass. This is because the cold temperature of the glass is cold enough to make water vapor that comes in contact with it change states back to liquid form.

The same principle happens on your air conditioner’s indoor coil, also known as your evaporator coil. The refrigerant that passes through this coil is extremely cold, which means the coil itself at this point is also extremely cold. The passing water vapor in the air that’s forced over your coil condenses and sticks to the coil. The air that continues through your system and is blown out into your home through your ductwork is then significantly cooler and drier because the water vapor that was in the air making it feel humid has been removed.

Why Is There Flooding?

As you may be able to imagine, the flooding you’re experiencing in your air conditioner is merely the result of your air conditioner removing so much humidity from the air. The water that’s extracted by your air conditioner needs somewhere to go—it can’t re-evaporate nearly fast enough, especially in the colder temperatures inside your air conditioner. What usually happens is the water drips down into your drain pan, a small metal pan that’s placed beneath your coil to catch runoff water. Your drain pan is connected to a drain line which carries water runoff safely away from your home. The drain line is typically a small pipe that leads outside your home.

However, over time, these drain lines can become clogged up. Whether it’s with dirt, leaves, or other debris, the clog prevents the condensation runoff from being able to drain away as normal. As a result, the water then accumulates in your drain pan until the pan itself fills up and starts to overflow. This is when you get the flooding that you suddenly notice. Unclogging the drain line isn’t usually difficult: simply use at thin wire like a coat hanger or a plumbing auger to remove the clog and the problem should disappear.

If you’ve got a problem with your air conditioner, have it inspected by a professional from the Kerrville HVAC team at 72 Degrees Air Conditioning & Heating! Call us at (830) 302-3140 today.