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Why Is My Air Conditioner Not Draining Water?

Dirty Drainpipe From Air Conditioning

Air conditioners are ideal for keeping rooms cool on hot summer days and improving air quality. However, if you notice that the AC unit is not draining water, you should be concerned.

A water drainage issue is a common problem with air conditioners. However, it might indicate a severe problem that needs your immediate attention.

This post will examine why your climate control unit is not draining water. Additionally, we will give a comprehensive guide on fixing the issue and ensuring that your AC is working optimally again.


If your air conditioner is having problems draining water, it might be caused by a clogged drain pipe, loose drain connection, or frozen evaporator coils. A defective condensate motor, dirty air filter, or leaking drain pan might also be the issue. Lastly, water will have trouble flowing into the drain pipe if your AC is not installed correctly.

Regular maintenance of your AC unit is an excellent way to prevent it from malfunctions, including drainage issues.

Why Does Your Air Conditioner Drain Water?

Water Flows Into The Drain.

As we mentioned before, your aircon plays a crucial role in improving the air quality around your house. One of the ways it does this is by removing any excess moisture in the air.

Air conditioners also couple up as dehumidifiers. As heat from the air is removed from the evaporator coils, excess moisture is also cooled down and removed.

The water condenses along the evaporator coils, drips down, and is collected in the condensate pan. The pan needs to be regularly emptied to prevent the water from freezing in the split AC or leaking. When the pan is full, water flows into the drain pipe, where it is safely removed outside your house or office.

Self-evaporating Air Conditioners

Unlike other AC units, self-evaporating air conditioners do not rely on drain pipes to dispose of the water. They can heat the moisture into vapor and release it outside or reuse the cold water to cool down the room quickly.

7 Reasons Why Your Air Conditioner Is Not Draining

If you notice that the drain pipe has not dripped water for a few days, it might mean something is wrong with your climate control unit.

Here are some things to look out for if you have this issue.

1. Clogged Drain Pipe

Clogged Plastic Drain Pipe

A clogged condensate pipe is the most common culprit for a drainage failure in your air conditioner. Dirt, debris, and pollen from the evaporator coils can easily dislodge and fall into the drain pan as the condensate collects. As the water drains from the pan, it can get into the drain pipe, causing a blockage.

How To Fix a Clogged Drain Pipe

First, you can flush the line with warm water. Gently disconnect the pipe from the back of your central AC, and pour water into the line using a funnel. The water should dislodge any debris that is stuck inside.

Secondly, a wet/dry vacuum cleaner can also do the job. Find a vacuum nozzle that is the proper size to insert into the drain tube outlet to ensure you get the best suction efficiency.

Using A Long Pipe Cleaning Brush

If you plan to flush the pipe or use a vacuum, an extra-long flexible pipe cleaner can also help remove stubborn debris. Gently scrape out the dirt to prevent damaging the tube.

Lastly, if the pipe is too clogged, it will need to be replaced. Before buying the replacement, you should inspect the size of the drain pipe connection to the HVAC.

2. Disconnected Drain Pipe

Condensation Drain

It might seem obvious, but the AC might have a loose condensate pipe connection. Vibrations from the air conditioner can cause wear to the link, loosening the tube. Water can also weigh down on the line, which stresses the connection.

Fixing a Disconnected Drain Line

Fixing a loose connection is a relatively straightforward process. All you need to do is inspect the condensate drain valve. If you notice any water leaks, the connection needs to be tightened.

A faulty drain valve should be replaced as soon as possible. Always buy an original equipment manufacturer (OEM) part for your AC model.

3. Frozen Evaporator Coils

White Ice On The Coil, Inside The Air Conditioner.

Frozen evaporator coils can also cause the HVAC to have drainage problems. As previously stated, the evaporator coils are responsible for heat and water removal in the aircon system. However, when the coils are frozen, it can prevent adequate heat transfer, causing water in the drain pan to freeze.

Thawing Frozen Evaporator Coils

There are several reasons why your unit’s coils might be freezing. An AC repair expert should look at the issue to solve it permanently.

However, before calling for help, you will need to defrost the evaporator coils. You must shut off the aircon unit and let the water drain. It should take about 24 hours before all the ice thaws out.

4. Faulty Condensate Pump

A defective condensate pump might also be the culprit. The pump pushes water from the drain pan into the condensate line. When the condensate pump burns out, water is retained in the pan, leading to drainage issues.

Malfunctions in the pump can also lead to the air conditioner shutting off unexpectedly. This prevents the drain pan from overflowing and leaking.

Replacing a Faulty Condensate Pump

Unfortunately, if the AC’s condensate pump is damaged, the best solution is to replace it. Because the pump is located near delicate components in your unit, it should be replaced by a qualified HVAC professional.

5. Clogged Air Filter

The Process Of Clean And Wash The Air Condition

Likewise, a dirty air filter can also cause your air conditioner to have a problem draining water. The filter in your indoor unit helps trap dirt, dust, pollen, and debris in the air from reaching the evaporator coils.

However, a clogged air filter can interfere with the heat transfer process in the evaporator. The dirt prevents proper air circulation to the unit, which can lead to water freezing in the condensate pan.

How To Clean Dirt Air Filters

Before cleaning, you need to turn on the device and remove the filter. You can use warm water and mild detergent to remove any dirt. Another option is brushing and vacuuming the filter.

Cleaning AC Air Filters

To avoid damaging the air filter, consult your AC user manual for the appropriate cleaning procedure.

6. AC Unit Not Properly Installed

Installation Of The Air Conditioner

The wrong installation of your air conditioner might also cause the issue. If your unit is not perfectly level or is tilting forward, water accumulates at the front of the drain pan instead of flowing into the condensate pipe at the back.

How To Adjust the Angle of Your Air Conditioner

You can fix the issue by readjusting the air conditioner, so it drains better. Slightly lower the back of the unit so water can properly drain out the pipe.

7. Leaking Drain Pan

Air Condition Unit Refrigerant

Lastly, the drainage issue might also be caused by a leaking condensate pan. If the pan is damaged, the water will be drained into the unit, leading to electrical problems. Additionally, when water leaks into your floor or walls, it might cause mold growth.

How To Replace a Damaged Drain Pan

Though you might be tempted to fix the drain pan using water sealant glue, the best option is to replace it. Buy a genuine drain pan that is recommended for your AC unit.

During replacement, shut down the appliance and gently remove the front panel. Unfasten the screws holding the condensate pan and slowly detach it from the unit. Secure the new pan to the air conditioner, and reinstall the front panel.


An air conditioner needs to drain water after dehumidifying the room. If you notice any drainage problems, they must be addressed immediately to prevent expensive repairs to the unit.

A loose drain connection or clogging in the drain pipe might be why the AC device is not draining water. Frozen evaporator coils, a defective condensate motor, or clogged air filters might cause the issue. Furthermore, a damaged drain pan or improper installation of the air conditioner can be responsible for drainage problems.

Frequently Asked Questions

What Happens if Your AC Air Filter Is Dirty?

The air filter is responsible for trapping dirt and debris in an AC. If dirt clogs up the filter, it restricts airflow to the unit, leading to heat transfer issues and frozen pipes. Furthermore, it also strains the evaporator motor, which could burn out and cause the device to overheat.

How Do I Fix My AC Not Draining Water?

Before opening your air conditioner to fix the drainage issue, it is crucial to identify its cause. Here are a few things to try to solve the problem:

  • Tighten any loose drain pipe connections.
  • Flush or vacuum a clogged drain pipe.
  • Defrost the frozen evaporator coils.
  • Replace the malfunctioning condensate pump.
  • Clean the AC’s air filter.
  • Replace the damaged drain pan.
  • Readjust the position of your air conditioner.

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