How To Clean AC Drain Lines (Vinegar Vs Bleach Compared)

An AC unit is designed to help you control the environment you live in. There’s a lot going on internally within your air conditioner to keep your air cool, and the AC drain line is a vital part of the mechanism.

Within your AC, the evaporator coil is used to cool the warm air down and moderate the moisture levels. However, condensation can build up around the coil and needs to be drained, or it can impact the performance of the air conditioner. The drain line is used to remove condensation liquid from your device and outside of your home.

It’s important that this is kept clean, and in this guide, we’ll explain the best ways to go about cleaning your AC drain line.

Why You Need To Clean Your AC Drain Line?

Your AC will produce a lot of moisture in its regular operation, and this needs to be drained to keep the machine working properly. Your AC drain line, or condensate line, is used to get rid of this moisture and keep excess water to a minimum. The moisture within your AC isn’t always clean, and other contaminants can make their way in. Over time, this can block your AC drain line and prevent water from emptying from the conditioner.

If your AC drain line becomes blocked, moisture will build up within the machine. This can make the air going through your system more humid and can have a negative impact on your home. The water itself can damage the internal mechanism of your air conditioner, leading to rust or even electrical faults. Even if the blocked drain line doesn’t stop your AC from working, it can impact the overall efficiency. Your AC unit will have to work harder and can start using more power to operate.

In some cases, the dirt within your AC drain line, combined with the moisture, can even lead to mold or bacteria. This can then spread into your home and become hazardous to you and your family. It’s therefore essential to keep the drain line clean.

Clean AC Drain Line

Where To Find Your AC Conditioner Drain Line

Your AC drain line is located outside of your home as it needs to be able to drain the moisture away. It’s usually found next to the condenser unit, coming out horizontally and then going straight down vertically. At the top of the AC drain line is the condensation tray, and you can usually lift this away to access the drain line and clean it.

Your AC drain line may be located in a slightly different place, and you might need to consult your user manual. You’re looking for a thin pipe on the exterior unit which allows water to drain from the machine.

Signs That Your AC Drain Line Could be Clogged

So, you’ve found your AC drain line, but how do you know if it’s clogged? It’s not always obvious, but we’ve given a quick breakdown of the common issues that mean there’s an issue with the drain line:

The AC Stops Working

Most AC units can take over 30 gallons of water from the air inside your home, and this all needs to go somewhere. It can be hazardous to have that much moisture remain within your machine, and most modern AC units have a sensor that detects excess liquid and shuts the conditioner down.

If your AC stops working, you should check the condenser pan to see if it’s full, and then see if the water is flowing out of your drain line as it should. You may need to clean it out before you can restart the AC unit.

Water Dripping Around The Inside Unit

Most AC units have an interior and exterior unit. If you start to notice moisture around the base of the interior unit, it can mean that there’s too much liquid in the machine. The most common cause of this is a blocked drain line, and you’ll need to clean it immediately.

The AC Drip Pan Is Full

The condensation and moisture from your AC first fills a drain pan and then drips down the drain line. If you notice that your drain pan is constantly full or taking longer to empty, it may mean your drain line is clogged. You’ll need to clean it to get the water flowing again.

Muggy Air Inside The House

If the air starts to become more humid, it usually means that there is excess moisture. This can be caused by a clogged drain line because no water is being emptied from the AC. Check the drain pan and drain line first but do bear in mind that muggy air in your home can also be caused by a faulty pump. Dehumidifiers can be beneficial in this instance.

Musty Odor

A musty odor in your home is generally caused by mold. It’s a tell-tale sign that there’s too much moisture in the air and could indicate that your drain line is clogged. By removing mold and bacteria from your drain line, you can help remove this smell from your home.

Related Article Reasons Why AC Smells

Visible Water Damage

Visible water damage is a clear sign that your AC unit isn’t draining well. If you haven’t used your machine in a while and can see water damage, you should immediately check your drain line to see if it needs cleaning.

Using Bleach Or Vinegar For Cleaning Drain Lines – Which Is Better?

There’s often a debate about whether you should use bleach or vinegar for cleaning home appliances and what gives the best results. Bleach is a common household cleaner that’s associated with removing tough bacteria and stains. However, it’s known for its abrasive nature, and it can be hazardous to your health if not handled properly.

Vinegar mixed with water is commonly used as a cleaner because of its acidic properties. It’s natural but can help dissolve bacteria and other waste leaving you with clean pipes. Vinegar is often used as a cheaper household cleaning agent, which is gentle but effective.

When it comes to cleaning your AC drain lines, you should always opt for vinegar. Bleach can be too rough on the machine and can have a corrosive effect on your drain line. This can cause lasting damage to the unit.

On top of this, bleach can be a hazard to your health, and if any gets into the AC, you could have some particles blowing around your home and being breathed in. Vinegar is a gentler way to clean your drain line, which will remove harmful bacteria with no risk of damaging the AC unit. It’s also a natural substance, and there’s no health risk associated with it. Always go for vinegar when cleaning your drain line.

Bleach or Vinegar to Clean AC Drain Line

How To Clean The Air Conditioner Drain Line With Vinegar (Step-By-Step Guide)

Cleaning your drain line isn’t too tricky, and anyone will be able to do it. For this method, you should make sure you have some towels, vinegar, and a pipe brush. You should be able to lift your drip pan and remove the cap with your hands, but if not, you can use a wrench or pliers. Once you have your equipment, you should follow these steps:

1. Turn Off The Power

Turn off your AC unit at the machine and at the breaker. This will make it safe to carry out work on the unit.

2. Locate The Drain Line

Go to the exterior of your unit and look for the drain line. This is a small PVC pipe that is usually attached to the wall of your home and located near your condenser unit. Your split AC drain line will go through the wall next to the interior device so you can follow it through to the outside of your home to find the pipe. If you can’t find it, then you should consult your user manual.

3. Find The Drip Pan

On the top of your drain line, there should be a drip pan or drain pan. This will fill first before water is drained from your home. You should be able to lift the drip pan off the drain line. This will allow you to clean the drip pan and access the drain line.

4. Clean The Drip Pan

Soak the drip pan in warm water for about 30 minutes and scrub clean. Use your pipe brush and vinegar to scrub any stubborn stains from the pan. Leave to the side while you clean the drain line.

5. Inspect The Drain Line

Look down the drain line and look for any visible blockages. Start by pouring some water through the drain to see if the blockages are moved.

6. Flush The Drain

Pour about ¼ cup of distilled vinegar down the drain line to help flush it clean. You can add some dish soap, but it isn’t really needed. Leave this to sit for about 30 minutes to work.

7. Flush With Water

Pour hot water through the drain line to wash the solution clean and remove any bacteria or blockages. Make sure water is flowing freely.

8. Clean The Drain Line

Take your pipe brush and push it through the opening and down as far as it will go. Clean all sides of the pipe and look to remove any blockages the vinegar hasn’t got to work on.

9. Reattach The Drain Line

Reattach the drip pan and make sure everything is connected securely. Turn the AC back on and make sure it’s all working as it should.

How To Clean The Drain Holes Of Window Air Conditioner

A window air conditioner has drain holes on the base of the exterior portion below the evaporator coils where excess moisture can flow out of the machine. Sometimes there are pipes connected to this hole, but some just leave the holes empty for water to flow.

The drain holes themselves can become clogged, and you’ll need to know how to clean them out.

Before you get started, make sure you have: a long, thin piece of wire, some hot water, and a cloth. Then you should follow these steps:

1. Turn Off The AC

Turn off your window air conditioner at the wall and at the breaker to ensure there’s no power going through the unit.

2. Locate The Drain Hole

Your drain hole will be found at the base of the exterior portion. If this is high up in your home, then you’ll need to use a ladder to reach it. A drainpipe may be attached, and you should be able to loosen and remove this by hand.

3. Clean The Hole

Feed the wire into the hole and start to rub it against the edges. Rotate it and use a teeth brushing motion to help remove any blockages from the drain hole. It should become easier to move the wire as it cleans.

4. Access The Drain Pan

If you still have an issue, then you need to clear the drain pan. To do this, you’ll need to take off the outer casing from the back of the AC to access the drain pan. You can do this while the unit is attached, or you can lift the AC unit off onto a clean, even surface.

5. Clean The Drain Pan

Use the warm water and your cloth to clean the drain pan and make sure there’s no dirt or blockages.

6. Reassemble The Unit

Put the AC back together again and put it back in place. Turn the power back on and make sure it’s all working correctly. Hopefully, it’s draining properly now.

How Often Should You Clean Your AC’s Drain Line?

It’s not difficult to keep your AC drain line clean, but the secret is consistency. You should look to clean your drain line every month as this helps to stop any blockages from developing. By taking the time to do this every month, you will prevent the AC from getting to the point where you can’t use it.

Alongside a monthly cleaning, you should have an HVAC professional inspect your unit once a year. They will check your drain line and hopefully clear it out for you if needed.

When to Clean AC Drain Line

People Also Ask (FAQ)

How can I stop my AC drain line from clogging in the future?

Regular cleaning is the key to keeping your AC drain line unblocked. Look to clean it out once a month if you can.

How much does it cost for an HVAC pro to clean the AC drain line?

It can cost anywhere from $75 to $250 to get a professional to clean out a clogged AC drain line.

Can you replace the AC drain line?

Yes, it is possible, but it can be challenging to do yourself. If you need to replace your AC drain line, you should consult with a professional to see if they can help you.

How much water should be coming out of a drain pipe?

Water will usually come out of your AC drain line in small bursts to help prevent it from freezing in the pipe. Expect it to come out in 300ml bursts about once a day, depending on how often you are using the AC.


Without a working drain line, your air conditioner won’t be able to work properly, and it can even negatively impact the environment within your home. Your AC drain line is a vital piece of your air conditioner, and it needs to be looked after. Hopefully, this guide has given you some useful information, and you now know how to properly clean your drain line yourself.

Josh Mitchell

Josh Mitchell

My name is Josh and I am obsessed with DIY and improving my family home. HVAC topics can be tricky for homeowners so I decided to share my knowledge on the subject. When I am not working on DIY projects, you can find me at the beach or my local coffee shop.