Water Not Coming Out Of Ac Drain Pipe – Why And What To Do?

You noticed that there's no water dripping from your AC drain pipe, should you be bothered? Is there something wrong with your AC and what can you do about it if ever? We researched to find expert recommendations, and here is what we've learned.

Water is not coming out of your AC drain pipe due to any of the following reasons:

  • disconnected drain line 
  • rusty or broken drain pan
  • defective condensate pump
  • damaged evaporator coil
  • dirty evaporator coil
  • clogged drain line 

Check these components to see what's causing the problem so you can do the necessary action for repair.

Continue reading to find out more about these reasons and possible solutions so that you can get the water draining out of your AC pipe smoothly. 

ac drainage pipe at the back of a house, Water Not Coming Out Of Ac Drain Pipe - Why And What To Do?

Why is my AC not draining water?

Your AC drains water as part of its normal operation. In case you're wondering why there's water coming out of your AC in the first place, it is because of condensation.

Science tells us that condensation happens when warm air meets cold air. Your AC sucks warm indoor air and as it travels through the cold evaporator coil inside the AC, it produces moisture or droplets of water. This water accumulates in the AC's condensate pan or drain pan until it is released out of the unit through the water outlet at the back.

Otherwise, water will continue to accumulate inside and will either leak through the gaps or stay inside and cause damage to your AC's internal components.

Your AC normally drains 5 to 20 gallons of water per day, so it can get really baffling when there's no water coming out of the drain line. It means that the cooling system isn't draining properly, and it could have an awful effect on your cooling unit.

If the water isn't draining, there are four parts that you need to check:

  • the drain line,
  • the condensate pan,
  • the condensate pump,
  • and the evaporator coil.

There could be several reasons why water isn't draining and we'll discuss them below along with the possible solutions.

ac drain pipe disconnect and possibility of clogged

What should you do when your AC is not draining?

Here are the reasons why the AC is not draining water properly and what you can do about them.

Just a reminder, always exercise caution when handling electrical appliances. Turn the unit off and switch off the circuit breaker before you proceed to inspect what's wrong with the parts mentioned above.

Drain Line Disconnection

The AC drain line is responsible for removing excess moisture from your cooling unit. It is a PVC pipe that is connected to your indoor air handler unit and extends all the way outside of your house. 

When water is not draining, it could be as simple as the drain line being disconnected from the air handler unit. It can be due to improper installation or the pipe being displaced due to constant vibrations.

Check the connection and make sure that the drain line is attached tightly so that the water can flow smoothly from your AC down to the end of the pipe.

Rusty or Broken Drain Pan

The drain pan is located below the evaporator coil so that it can immediately catch excess moisture from the condensation that usually happens in this part of the AC unit. It can be made of metal or plastic.

The drain pan might be worn out, especially if you've had your AC for a long time. There could be cracks or corrosion on its surface preventing it from catching water properly.

If it's rusty, check if you can still clean the pan. Remove it from your AC carefully. Use sandpaper to remove the rust, then brush it with soapy water. Let it dry completely after rinsing.

But if the pan is damaged already, you need to have it replaced so that it can catch the water as expected. 

Rusted drainage pan for an ac which is worn out close up shot.

Defective Condensate Pump

Some units have this pump to push moisture or water efficiently into the drain line. If this component is not working, water won't reach the drain line.

a condensate pump

Damaged Evaporator Coil

Evaporator coils can get damaged over time due to corrosion. When this happens, water will just usually leak at that side of the AC instead of going to the drain line.

This problem requires immediate action because it can lead to further issues. The leaking water can damage your wall and carpet. It can also lead to your AC malfunctioning and blowing hot air instead. It may also cause a short circuit or your AC might not work altogether.

Call an HVAC technician to have this problem fixed.

ac condenser coils photographed up close

Dirty Evaporator Coil

It could also be that the evaporator coil is clogged with dirt that's why water can't flow toward the drain pipe. When dirt is blocking its way, and the water is stuck in this portion, it would lead to leaks instead.

So better have your coils cleaned properly to avoid this problem.

a dirty condenser coil of an ac

Clogged Drain Line 

Dust and debris can accumulate in your drain line over time, and they can get to the point wherein they won't allow water to pass through.

ac cooling air pipes covered by snow or frozen because of super performance of heavy duty central air

Here are the noticeable signs that you can observe when you have a clogged drain line.

Signs the AC Drain Line is Clogged

  • water puddling under the air handler unit
  • standing water in the condensate pan
  • water damage on the carpet or wall underneath the AC
  • musty smell in the room or throughout the house
  • more frequent allergy attacks and headaches
  • AC blowing hot air
  • AC not working at all

How do I unclog the AC drain line in my house?

There are different ways to remove the blockage in your drain line.

Using a Vacuum

Suck the dirt out using a wet/dry vacuum cleaner. Position it over the drain pipe. You can put a piece of cloth around the pipe if the vacuum nozzle is too big so that you can get a tight fit. Turn off the vacuum cleaner after a minute.

Using a Thin Wire Brush

This is a little bit more complicated than it sounds. Aside from the long wire brush, you also need a piece of rubber tubing, a saw or PVC pipe cutter, and hose clamps.

Check out this drain brush on Amazon.

You need to cut part of the pipe near the drain trap. The drain trap is the curved part of the pipe where dirt usually builds up. Cutting the pipe will help you have easier access to this section so that you can clean it more thoroughly. 

Make a cut about a foot from the drain trap. You can put a bucket underneath the cut to catch the excess water. Insert the thin wire brush into the drain trap to clean it. Push it back a couple of times to get rid of the dirt that's clogging your drain line. You can check if it has been unclogged by pouring water on the condensate pan and it should flow smoothly out of the pipe.

Once the clog is cleared, you can reconnect the pipes by inserting the rubber tubing on one side and sliding the other pipe inside it. Put the hose clamps on both sides to secure their coupling.


Check out this video to help you get rid of the clog in your AC drain line.

Can I use vinegar or bleach to unclog the AC drain?

Bleach and vinegar are two popular cleaning agents that you most probably have at home. You can use either one to unclog your AC drain. They can help you get rid of the dirt and bacteria that have settled in your drain pipe.

But if you have to choose between the two, choose vinegar instead. It is milder than bleach and won't cause corrosion to your drain pipe. Do not attempt to use both together as their combination can result in chlorine gas poisoning. 

Take off the drain pipe's plastic cap or plug. Remove as much dirt and debris as you can. Pour a cup of distilled vinegar into the pipe. Mix equal parts water and bleach if you don't have vinegar. Wait for about 30 to 60 minutes to give the cleaning agent enough time to dissolve the dirt. 

You can test if the clog has been removed by pouring water into the condensate pan and checking if it'll now flow smoothly out of the pipe.

These are the things that you can do when your AC is not draining water. If the issue is not resolved, call an HVAC technician to have it checked properly.

Final Thoughts

ac drainage pipe at the back of a house

Next time you notice that your AC is not draining water, you know what to do. Just check the drain line, drain pipe, condensate pan, and evaporator coil to know what's causing the problem and see if you can have it fixed by yourself or if you need to call an HVAC technician to help you out.

If you found this article helpful, you might also like to read the following posts:

Should You Add A Humidifier To Your HVAC?

How To Fill Gap Above A Window Air Conditioner?

Share this article

Leave a Reply

Your email address will not be published. Required fields are marked *