How to Unclog Your Air Conditioner’s Drain Line

One of the most important parts of an air conditioner is the drain line. It serves the purpose of pulling any humidity out of the air in your home. Any moisture will drip into the condensate pan, where it will eventually move through the drain line and exit the system. In order to keep the system working properly, that moisture would then need to be drained out of the condensate pan, through the drain line, and out of the system.

If your drain line is potentially clogged, this could lead to major issues such as a complete system failure. We’ve put together a list of a few different tips and tricks on what to do when your drain line isn’t working properly.

Signs that your drain line may be clogged

Many newer air conditioners have sensors that notify the homeowner when the line is clogged. For those with older systems, you may notice that your home feels warmer and more humid than usual. If the line is clogged, it will result in a holdup of water since it won’t be able to exit the system.

Other signs of a clogged drain line include puddles near your unit, rust along the base of the unit, any odors of mold or mildew coming from your A/C vents, and the unit blowing warm air. If your condensate pan overflows, it can damage any surrounding areas and will greatly increase the chance of growing mold or mildew. It could also lead to deterioration of the entire unit.

It’s possible to unclog your drain line on your own. But, it’s always best to reach out to the pros at Chas Roberts if you feel uncomfortable taking on this DIY job. Here are some tips if you are looking to fix your clogged line yourself.


Tips to unclog your drain line

Some air conditioners automatically shut off when the condensate line becomes clogged. This is particularly true of newer models. If your air conditioner did not shut off automatically, the first step is to turn it off yourself. You don’t want your air conditioner to continue running, as this introduces more water and more backup to an already clogged situation. There are several methods you can use to clear a clog from your drain line. It’s also always an option to contact an A/C professional and have them clear the clog and clean the drain for you if you’re not comfortable doing it yourself.

Wet/dry vacuum

A wet/dry vacuum can be used to remove any clogs in your drain line with the power of suction. You can rent one from most hardware or grocery stores. If your drain line clogs frequently, it may be a good idea to invest in one to have on hand. After turning off your air conditioner, locate your drain line runoff—the white or copper PVC pipe attached to the exterior of your home. Then, follow the following steps to use the wet/dry vacuum to remove the clog:

  1. Attach the vacuum hose to the end of the drain line. Make sure you have an airtight seal. You can secure a cloth towel or duct tape around the opening of the drain line to make sure there are no gaps between the vacuum hose and the drain line.
  2. Run the vacuum for 1-2 minutes.
  3. Open the vacuum and see if you’ve removed the clog. If you see a lot of brown-colored water, or some algae buildup, you likely removed the clog.

If the vacuum is empty, repeat step 2 as needed. If the clog does not clear after several attempts, you may have a severe clog that needs to be cleared by a professional.

Garden hose

If you don’t have a wet/dry vacuum, a garden hose can also sometimes be used to break up clogs with water pressure. The force of the water running through the drain can force the algae buildup out of it. Follow these steps to make this method work:

  1. Connect the head of the garden hose to the opening of the condensate drain.
  2. Maintain a tight connection between the drain and the hose with your hand and run the hose on high in short bursts. This should allow the water to travel upwards and break up any clogs in the drain.
  3. Repeat step 2 until the water runs clear.

Vinegar or hydrogen peroxide

This method involves pouring a liquid down the drain line access pipe with the intent of breaking up the clog internally. The drain line access pipe is located near your indoor unit, which may be in your attic, crawl space, or garage, typically installed on top of the gas furnace in your home. Simply pour a cup of vinegar or hydrogen peroxide down the drain and let it sit for 30 minutes while the chemicals begin to make their way through the drain. This can help break down the clog, making it easier to pass on its own. After the 30 minutes is up, flush the drain with water to ensure everything is flowing as it should.

How to prevent drain line clogs

Clogs in your drain line can be annoying, but they’re also preventable. Before you turn on your air conditioner on for the start of the cooling season, pour a cup of bleach down the drain line access pipe. This will prevent bacteria, mold, and mildew from growing in the first place, keeping the drain clear all season long.

Many companies also inspect and clear the condensate drain line during a standard maintenance visit. As part of our exclusive 26-point maintenance plan, an expert Chas Roberts technician will clear any existing clogs in your condensate drain line, along with inspecting the whole system top to bottom to ensure that there’s nothing standing between you and clean, cool air.

From drain lines to compressors, Chas Roberts knows air conditioning

If your condensate drain line is clogged, or you have other A/C issues that need fixing, there’s only one name you need to know: Chas Roberts. With over 75 years of experience, we’ve helped families throughout the Valley for generations. Contact us to get started.