How to Clear a Clogged Air Conditioner Drain Line

An air conditioner drain line is essential and functions by removing water from the evaporator unit in the air conditioner unit. Also, it converts the cooling refrigerant’s matter state from liquid to gas state. After using the air conditioner drain line for a long time, mold or any other substance may grow, resulting in the clogging of the air conditioner drain line.

Cleaning the air conditioner drain line is easy as long as you assemble all the essential tools to carry out the activity. Luckily, the article gives the best ways of unclogging the clogged air conditioner drain line within less time and without help from skilled personnel.

Signs of a blocked air conditioner drain line

Signs of a blocked air conditioner drain line

The following signs will help you detect clogging of your air conditioner drain line.

i. Failure of the air conditioner system to function at all or to function normally. The air conditioner fails to perform its cooling functions due to the clogging of the drain line.

ii. Production of bad smell, especially moldy smell near air conditioner vents. With time, the foul smell may increase, polluting the environment and affecting the health of the surrounding people.

iii. Water filling near the air conditioner unit or air handle.

iv.  Air conditioner condensation pan failing to drain water.

v. Distortion of different air conditioner units especially, parts near the AC or fan.

vi. The air conditioner automatically fails to turn on after shutting down.

Cause of clogged air conditioner drain pipe

Cause of clogged air conditioner drain pipe

The leading cause of clogged air conditioner drain lines is the growth of mold or algae. Warm water passing over a cold HVAC cold evaporator increases humidity in the drain pipe. Humid increases in the drain line provide the best conditions for the growth of algae or molds.

Also, the drain line may clog due to the accumulation of dirt and rust. While warm air flows through the cold evaporator, it may contain some dirt that can accumulate in the drain line and clog the drain lines. Also, if the drain line is made of material that easily rusts, continuous rusting of the material results in the accumulation of dirt, thus clogging the drain pipe.

Steps on how to clear a clogged air conditioner drain line

how to clear a clogged air conditioner drain line

Unclogging the clogged AC drain line is accessible for both professionals and non-professionals. The following steps describe the process of unclogging the clogged AC drain line.

Step 1: Collect all materials required

The material required includes; a dry and wet vacuum, a funnel, clean rags, vinegar or any recommended agent, a thin wire brush, and rubber gloves to protect your hand from injuries.

Step 2: Shut down the air conditioner

First, disconnect the AC from the power supply source. Turning off the AC unit powers off the thermostat the AC breaker. It is advisable to turn off the AC unit before removing molds or algae from the drain line to get accurate results.

Step 3: Locate the air conditioner drain line

After turning off the HVAC system, find the location of the drain line. Inspect the AC condenser unit outside the HVAC unit and find the AC drain line. Using a bucket, empty the drain line by draining all water present in the drain line. Ensure the PVC pipe is empty before proceeding to the next step.

Step 4: Find the drain line access point

Inspect the drain line for a T-shaped vent with a cover. Open the vent by removing the lid and scrutinize the drainpipe to detect any blockage. Ensure you wear protective clothing such as gloves, a protective suit, and a face mask to prevent inhaling the moldy smell.

Step 5: Remove the clog using a thin brush

After inspecting the drain pipe for any blockage, push the thin brush down the drainpipe to remove the clog manually. If the thin brush fails to remove the clog, consider using other methods such as using distilled vinegar to remove the clog. While pushing the thin brush down the drain line, ensure you wear protective gloves to protect your hands from touching any mold or dirt.

Step 6: Use a wet or dry vacuum to remove dirt

If the thin brush fails to remove the clog, use a wet or dry vacuum. Connect the end of the air conditioner drain line to the chosen vacuum using tape, especially duct tape. Switch on the wet/dry vacuum to suck all dirt from the drain line.

Step 7: Use distilled vinegar to remove the clog

Sometimes, both thin brush and wet/dry vacuum may fail to remove the clog. In such a case, proceed to using distilled vinegar. Vinegar is preferred in that it is acidic and can remove stubborn dirt. Make a vinegar mixture by mixing vinegar with soap and warm water to reduce the pungent vinegar smell.

Flood the drain line with distilled vinegar and leave it for approximately 25 minutes for accurate results. Also, you can leave the vinegar for longer if you are not in a hurry. Also, vinegar removes the moldy smell from the AC drain line.

Step 8: Clean the drain line

Using the appropriate cleaning agent recommended by the technician, clean the PVC pipe by pouring the cleaner down the cleaning pipe. It is advisable to use the recommended cleaner to avoid damaging the PVC pipes.

Step 9: Rinse the PVC pipe

After thirty minutes, flush the drain pipe with water to complete the process. Repeat the flushing process until the drainpipe is clear. Inspect the drain pipe after rinsing to see the water is flowing out of the AC drain pipe. To inspect the drainpipe, tell someone to watch outside if water flows out of the drain line.

If the drainpipe remains clogged, repeat the process above until you obtain accurate results. Also, if the problem persists, consider contacting skilled personnel for help.

Step 10: Reinstall all components removed during the unclogging process

Once the drain line is free from mold or any dirt, reassemble all AC components and reinstall them to their correct position. Switch on the AC and test it to ensure it is functioning as required.

Step 11: Redo the process often

To maintain the AC and the AC drain line, consider carrying the clearing activities at least twice a month to improve the functioning of the AC and the AC drain line. Finally, if you don’t have a vacuum, consider using available materials such as surgical tubing to remove the clog.

You might be interested to read also: Bryant Air Conditioner Troubleshooting


 If your drain pipe clogs, first try inspecting the whole AC and fixing the problem on your own. Luckily, the article gives the step-by-step process of clearing a clogged air conditioner drain line to remove all clog. Ensure you follow the steps carefully to get accurate results.

Finally, follow the manufacturer’s guidelines on how to handle an AC system. Moreover, service your AC regularly to improve its performance.

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