Basics on AC Drain Line Clogs

When your home’s air conditioner cools down areas of the home, it’s not only removing heat – it’s also removing humidity, or moisture, from the air. In a working system, this moisture collects in what’s called the condensate drip pan, then is pushed into a tube that leads outside and released.
At AirNow Cooling & Heating, we’ve seen a number of examples of clogs in this drain line. How do these take place, and how can you spot them and address them if they happen? Let’s take a look.

How Clogs Accumulate

All the water that collects in the condensate pan contains particles and bacteria found in the air it was pulled from. As more and more of it collects in the pan, it can leave behind a residue – this residue will sometimes form mold, algae and clumps of dust or dirt.
It’s also possible for clogs to form on the end of the drain line closer to outside, particularly if the drain line already spits out to a dusty area. Finally, it’s also possible for clogs to accumulate in this drain line if it hasn’t been used in a long time, allowing insects to build a nest and clog it that way.

Clog Signs

In many cases, modern HVAC systems are built to detect a clog in the AC drain line – in these systems, a shutdown will take place automatically if the drip pan becomes too full. Smart systems can even send a message to the owner when this happens, notifying them that it’s time to empty the drip pan.
For systems that do not have these features, picking up a clog is a bit tougher. You might not see any visible signs until water begins to drip out of the ceiling or vents, which is a signal that the drip pan is already overflowing. In these cases, shut down the AC unit right away and call our pros for AC repair.

Cleaning Drain Line Clogs

In most cases, we recommend allowing our professionals to clean a drain line clog, which requires equipment like an air compressor and other pieces. For those who want to try cleaning themselves, you have to first locate the drip pan (usually at the bottom of the unit), then carefully slide it out and use a wet/dry vacuum to remove standing water. Wash the pan well.
From here, use suction or positive air pressure to clean the drain line itself. This can be tough in some cases, and you may have to try various vacuum attachments. You can also try an air compressor to blast air into the drain tube and blow out a clog. Once the drain is clear, pour a gallon of white vinegar through it slowly to kill and mold or algae left over.
For more on identifying and clearing an AC drain line clog, or to learn about any of our other air conditioning repair services, speak to the pros at AirNow Cooling & Heating today.