How to Clean a Condensate Drain Line

A central air conditioner‘s condensate drain line is crucial to its functioning.

That’s why you need to perform routine maintenance to prevent it from clogging.

We’ll talk about how to do that, but first, it’s important to understand how central air conditioning works.


2 ac units
Air conditioners keep the inside of your house cool and the humidity low.

All About Air Conditioning

In addition to cooling your home, an air conditioner removes moisture from the air. This process lowers the humidity level inside your house.

Any excess condensed water is removed from the air conditioning unit through a small drain pipe that extends from the indoor air handler to outside your home. This drain pipe deposits the excess condensed water outside on the ground.

Walk outside your home and look at the condensate drain line. At any given moment, especially during humid weather, you should see water dripping from it. That’s the drain line in action!

Now, if you don’t see the drain line dripping, chances are, it’s not draining. And that’s a problem.


a plugged condensation drain
The condensation drain needs to be free of blockage to keep your AC running smoothly. (Adobe Stock photos)

Unclogging a Condensate Drain Line

Over time, algae, mold and mildew can build up inside the condensate drain line and form a clog. This causes water to back up and overflow inside the air conditioner unit.

Preventing this from happening couldn’t be more important, and fortunately, maintaining your air conditioner’s drain line couldn’t be easier!

Just pour a cup of bleach in the drain line’s access opening near the indoor air conditioning unit. This will kill any algae, mold or mildew that has formed in the pipe.

If the condensate drain line is clogged, you will need to use a wet-dry vacuum or a special pump to unclog the line.

Watch this video to find out more.