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Pacific Sheet Metal Blog

6 Quick Steps to Unclog Your AC Drain Line

Posted by Joey Haack on Feb 9, 2022 11:13:05 AM | Updated on 03/08/22 12:07 PM

6 Steps to Unclog Your AC Drain Pipe


Your air conditioner is an important part of your home. Not only does it keep your house and family cool and comfortable in the hot summer months, but it also helps maintain indoor air quality and regulate your home’s humidity level. The air conditioning unit does this by collecting water vapor from the air throughout your home and sending it outside through an attached drain line.


Unfortunately, this wet, dark drain pipe is the perfect environment for mold and bacteria to grow. Over time, this growth can build up and clog the drain line, preventing it from doing its job effectively. It is very important to keep this drain pipe clear to prevent leaks and water damage. If you notice signs of a clogged drain line, it’s best to address the problem as soon as possible.


Clogged Drain Line


How can I tell if the drain line is clogged?

There are a few different ways to tell if you need to unclog your AC’s drain line. The most obvious and severe symptom is an air conditioner either that stops cooling your home or just won’t turn on. Other signs of a clog include

  • Water dripping from the air conditioner
  • Higher than usual energy bills during cooling season, as a result of your AC unit working harder to do its job
  • Musty smell coming from the air conditioner, which can develop due to the bacteria buildup within the pipe
  • Full drip pan, which can trigger a safety sensor to shut the system completely off.


If you have a newer HVAC unit, it may include sensors that will alert you when the drain line is clogged and needs attention. Otherwise, it is up to you to regularly check the line.


How do I fix a clogged drain pipe?

As soon as you suspect your AC’s drain line is clogged, it’s important to take action. Despite what you may have heard, run-of-the-mill drain cleaners are not safe to use in your AC’s drain line unless they are copper or aluminum safe, which is rare. A good rule of thumb is to never use anything stronger than a basic vinegar solution to avoid corroding or otherwise damaging the pipe.


Perhaps one of the easiest and safest ways to clear a clogged drain pipe is by blowing it out with compressed air. If you are unfamiliar with this type of work, it would be best to contact a professional.


Here are some easy steps to take to clear the line yourself:

  1. Turn off your air conditioner, including the thermostat and the circuit breaker panel to avoid a shock or electrical damage.
  2. Locate the drain line, which typically is made of PVC pipe and has a plastic cap, which you will need to remove.
  3. Remove any visible blockage, but be careful not to accidentally push it further down into the pipe.
  4. Using a vacuum, shop vac, or air compressor, blast air into the drain line to blow the clog out the other end.
  5. Once the drain line is clear again, flush it with water to clean. You can use basic white vinegar, as well, but it is important to follow it with water to leave the drain line clean and mitigate the risk of future clogs.
  6. For good measure, remove the air conditioner’s drip pan (usually at the bottom of the AC unit) and wash it in hot, soapy water to remove any buildup.


If the above steps did not take care of the problem, it is time to call in an HVAC professional who knows how to take the unit apart and put it back together properly. If the clog is severe enough, it could require replacing the drain line completely, which is not a DIY project for the average homeowner.


Prevention is Key

The best way to keep your air conditioner’s drain line clear is to ensure it never becomes clogged in the first place! Make sure to change your air filters on a regular basis, and have a professional conduct regular routine maintenance to ensure your air conditioner runs efficiently for as long as possible and your indoor air remains safe.


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Topics: heating and cooling, plumbing, maintenance