Advanced Air

Why Is My Air Conditioner Leaking Water Inside My House? [FAQ]

July 09, 2015

Central AC leaking water inside your home, eh?

That’s not good.

First, turn off your AC to prevent serious water damage and hazardous electrical issues. Next, we highly recommend calling a professional HVAC repairman for help.

If you want to understand the cause of this problem read on.

In this article we’ll explain:

  • Why water forms in the inside AC unit
  • What causes the water to leak inside your home
  • How the problem can be fixed

Why water forms in an AC’s indoor unit

Condensation is a natural reaction that occurs inside all AC units.

You see, your AC’s job is to pull heat and humidity from the air inside your home. To do that, your system pulls in warm air through an indoor vent (called a return grille) and moves it across your inside unit’s cold evaporator coil to cool the air down.

When this happens, moisture forms on the evaporator coil. Just like the condensation that forms on a glass of ice cold water on a hot summer day.

Normally, the condensation on the coil drips into a drain pan and down a condensate drain pipe that leads it outside of your home (or into your plumbing system).

Now that you know why the condensation happens and the parts involved, here are a few  common problems that can cause water to leak inside your house.

Clogged condensate drain line or rusted pan

If your drain line is clogged–commonly by dirt, algae, insects or a dirty evaporator coilwater drainage is limited; causing a buildup of water with nowhere to go other than your home.

And because Florida is so hot and humid, your AC runs more often so it doesn’t take long for large amounts of water to build up.

What to do: You can use a wet/dry vac on the outside condensate pipe or have a trusted professional clear any major blockage with a special vacuum.

Also, the drain pan may be rusted through, allowing the water to fall through the pan and cause disastrous leaks and dangerous electrical issues inside your home. So, you’ll definitely need to replace the pan.

Improperly installed condensate trap

If your AC is fairly new, the problem could be with the way your system’s condensate trap was installed. An improperly designed condensate trap can block drainage and cause the drain pan to overflow with water.

What to do: You’ll need a professional to know what to look for in a condensate trap design and  to see if it needs to be reinstalled.

Frozen evaporator coil

Condensation on your cold evaporator coil can also freeze. If it does, there’s a clear problem with your AC. It can even freeze all the way down the refrigerant lines to the outside unit.

And when it melts, there can be a lot of unwanted water in unwanted places throughout your home. 

Common causes of a frozen coil include:

  • Dirty air filter
  • Low refrigerant
  • An airflow problem

Other issues...

There are a number of problems that cause water leakage from your AC but these are a few of the most common. We understand this stuff can get pretty complicated.

Note: Depending on where the inside unit is and what specifically is causing water to leak inside your home, the damage could be pretty significant and extremely dangerous. Many, if not all, of these problems require a professional to ensure safety and proper resolution.

Need help now?

Get it fixed today and schedule a repair with Advanced Air (scheduling online saves you 10>#/strong###).

Advanced Air has been serving Fort Myers and Naples, Florida, and the surrounding areas for over 25 years.