How to Clean an Air Conditioner Drain [Detailed Guide]

One of the commonest reasons you will need repairs on your air conditioner is an obstructed drain line. This article is a guide on how to clean an air conditioner drain.

How to Clean and Prevent Your Air Conditioner Drain from Clogging

The following are steps to take in order to clean your air conditioner drain:

Step 1

Disconnect the air conditioner from electrical power by turning off the breaker and the thermostat. Always disconnect electrical appliances from power if you want to clean them or make any repairs.

Step 2

Find the drain line; it is usually a pipe running out from the inside unit and is close to the condensing unit outside the house. It is easy to find because you will notice water dripping out of it from time to time when the air conditioner is running.

Step 3

You will need to locate the entry point to the drain line. There may be a cover over it and you must remove it to clean the drain line. Next, check to see if there is debris in the drain. If the drain is obstructed, pour a quarter cup of vinegar, the distilled type, into the drain. You can also use hot water with a little dish soap in it or peroxide in the place of vinegar.

Step 4

After pouring the cleaning agent down the drain, give it about thirty minutes and flush the drain with water. You will have to pour a good amount of water into the drain and keep doing it until the water runs free and clear. Ensure the water is flowing out of the drain pan.

Ensure you clean the drain in this manner every month or less if you want to keep the drain from clogging. Water alone is not enough, especially when there is a significant amount of dirt clogging it. Using vinegar or peroxide will kill bacteria and fungi such as algae, mold, and mildew. That way, you prevent hazards to your health.

Another method of cleaning the drain line of your air conditioner is using a wet/dry vacuum. Before using it, ensure you remove the paper filter so that you do not damage it. 

Next, go to the end of the drain and hold the hose to it. If there is a gap, plug it with a small rag or duct tape. Now, turn the vacuum on and allow it to run for a couple of minutes; it is enough time for the vacuum to suck the debris out of the drain.

Note: Use the user manual to find the exact location of the drain line and pan if you have a central air conditioner in your home.

Signs Your Air Conditioner Drain Is Clogged

The most common sign of a clogged condensate drain in your air conditioner is pooled water. You will also know the line is blocked when the unit begins to leak water. You may typically notice a negligible amount of water in the unit and it is nothing to worry about, but when the water increases and never stops, check the drain line.

Another indication of a blocked drain is a drain pan that is always full. When the water in the pan does not flow out as quickly as it should, leaving the pan full, it means the debris is blocking the line. It may also indicate that the drain pan needs emptying and cleaning. There is a danger of mold growth and damage to your air conditioning unit, as well as worsening allergies and asthma, if you do not clean the pan and drain line.

If none of the above is readily visible, the smell of mildew or mold can alert you to a problem with the drain line. If you have a central air conditioner, the smell may permeate the entire house. It is crucial to check the air conditioner drain line if an odd smell suddenly springs up in your house and you have a hard time locating the source.

Preventing a Clogged Air Conditioner Drain

It is pretty easy to prevent the drain line from getting clogged. First, ensure you use the correct type of filters for your air conditioner type and model. Not only that but also use high-quality filters. Cheaper options may be good but not good enough to filter the pollutants from the air.

Poor air filters may not prevent dirt from accumulating on the evaporator coil, leading to freezing and clogging in the drain. However, good filters, though pricier, will filter the air more thoroughly, reducing the chances of clogging. It is also important to replace the air filters once every three months or sooner if you smoke or have hairy pets.

It is crucial to clean the air conditioner as regularly as you clean your house. You do not have to wait until it begins to malfunction. Clean every part of the unit, including the fans, fins, and motors. And while you clean it, ensure you check and flush the drain line. Ideally, clean the AC every month and flush the drain line with vinegar or peroxide as often. Use the services of a professional for the best results.

Finally, regularly service the air conditioner. Two times a year, contact a technician to routinely check the unit. That way, you will see faulty parts before they turn into major problems. Not only does it save the unit, but it also saves you money.

Check out these other articles…

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Goodman Air Conditioner Not Working [How to Fix]

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Air Conditioner Blowing Hot Air/Not Blowing Hot Air [Solutions]

Air Conditioner Is Not Blowing Cold Air [Proven Solutions]

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How to Clean an Air Conditioner Drain Pan

To clean the drain pan in your air conditioner, first, inspect it. Locate the evaporator coil behind the front panel of the inside unit. Under it, you will find the drain pan. That is where condensate flows into and drains out of the unit through the drain line.

Disconnect power from the air conditioner and turn the thermostat off. Using a flashlight, check the condition of the pan, especially if the drain tube seems clogged. The pan may have debris in it, preventing water from flowing out. Clean it with soapy water or vinegar as well as you can. It may be difficult to reach it properly due to its location.

If the water is flowing out from the pan, it may not necessarily mean the drain line is clogged. It may mean that the drain pan is cracked and leaking. In such a situation, you need to replace the pan. But if the crack is not much, try sealing it with epoxy glue or water sealant.

Hire a professional HVAC technician to clean the drain pan if you are unsure of the cleaning process. An air conditioner typically has two drain pans; one is under the evaporator coil and is permanently fixed, while the other is farther down the line. Cleaning the permanent one may be difficult, hence the technician.

How to Clean Drain Pan on RV Air Conditioner

To clean the drain pan in your RV air conditioner, you will need to go to the roof of the rig. That is where you will find the shroud, which is the cover for the air conditioner to protect it from the elements.

When you remove the shroud, you will find a cover over the drain pan. Because it is screwed in place, you will need a screwdriver to remove it. The evaporator coil will become visible so, clean it along with the pan with a damp rag. 

Ensure there is nothing clogging the drain pan or the evaporator. The dirt can lead to more serious issues in the air conditioner. Put the cover back into place and secure it with the screws.


Clean your air conditioner drain every month but do not use too much water so as not to damage it. This guide on how to clean an air conditioner drain will help you clean one of the most intricate parts of the unit.

However, find and hire a technician to clean the entire unit, including the drain pan. That is because the unit tends to be difficult to clean thoroughly and you risk damaging a component. The technician may also service the unit to find possible faults.

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