Why is my Window AC Leaking Water – 2022 Guide

Window AC Leaking Water

On a pleasant Friday morning, as you abruptly wake up from your long-awaited sleep after a hectic week; to the sound of water dripping on your face, you may be thinking as you look at the source, why is my window AC leaking water??

Well, to be frank, water leakage from air conditioners is a very common sight irrespective of the age or viability of your AC and may occur due to several causes.

With the alarming spike in global temperature, air conditioners have become a necessity rather than a luxury.

Regardless of social class, people are seen buying air conditioners from a variety of price ranges, to ensure the comfort of their abode or workplace.

But this comfort comes at the price of maintaining the functionality of your air conditioner.
It can be hampered due to various reasons; water leakage being the most common one.

In this article, we will walk you through the most common causes of why your window AC may leak water, as well as the necessary steps to overcome the situation.

Why is my window AC leaking water?

If you want to know the answer to why is my window air conditioner leaking water? Read below to find out the most common causes of window AC leaking water.

Blocked condensation pipe

Blocked condensation pipe is the most common cause of water leakage from AC. This pipe works to drain the condensation from the overflow pan to the drain pipe. By doing so, it ensures the smooth running of your AC.

While the latest models of ACs are usually equipped with an automatic shutdown mechanism in case of overflow, the older models do not have such mechanisms and thus blocking off the pipe by dust, dirt, mold etc. cause the water to back up and flood your space.

Corrosion of condensation pan

Corrosion of the condensation pan can also cause water to leak through the pan.

But since the pan is usually located underneath the AC unit, it is also the easiest to identify.

Soiled air filters

Soiled air filters block the smooth airflow over the evaporator coil which freezes over time due to extreme cold. When it starts melting, the excess water may drip into the pan and flood it. And eventually, cause your AC to leak water.

Clogged evaporator coils

When the evaporator coils of your AC unit get clogged up with dirt or are damaged in any way, your AC will slowly start running less efficiently.

And due to the coils freezing up, your AC will start leaking in due course.

Insufficient refrigerant level

An insufficient or extremely low refrigerant level is one principal indicator that you might need to change your entire AC unit.

Similar to the effect of soiled air filters, a low refrigerant level lowers the overall pressure of your unit and causes the evaporator coil to freeze up. When it starts melting, the drain pan is overflown by the excess water and ultimately causes leaking of water through your unit.

Malfunctioning condensate pump

This cause is applicable for the air conditioners located in the basement of your house.
With a faulty or improperly installed condensate pump, the water cannot be channeled outside which may cause your AC unit to leak.

Defective sealing of AC to the window

Another reason for your window AC to leak water is defective sealing of AC to the window.
If your window AC is not properly sealed on all sides during installation, excess moisture accumulation will cause your unit to leak.

Poor insulation of ducts and vents

Properly insulated ducts and vents play a crucial role in transporting the condensation down the drain lines.

If the ducts and vents of your AC are poorly insulated, it may cause your unit to leak.

Continuous use of a unit with insulation issues will also cause a leaking unit.

Adverse weather or temperature

If there is excess moisture in the air outside your home or if it rains heavily often, water is less likely to evaporate.

This causes excess water moisture to form in the air conditioner that leads to leaking.

Faulty installation

Faulty installation of your AC can also cause leaking of water. You can get it fixed by calling in a technician.

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How can I fix it?

why is my window AC leaking water

Here are a few ways you can fix your leaking unit if immediate help is not available.
However, it’s best to get help from professionals.

Change/reset the thermostat settings

An often overlooked but common cause of water leakage is the thermostat settings.
Changing to new settings may solve the leaking issue.

Clean the air filters

The air filters of your AC are the most important part. They are the most prone to catching dust and dirt easily.

That is why cleaning them monthly is a must.

On occasions of frequent use, such as summer, cleaning the filters weekly will prevent future leaking.

Keep tabs on the parts prone to clogging

Since there are a lot of parts of an AC that are prone to clogging, it is necessary to always check them and make sure they are cleaned and do not clog up.

Removing the block will ensure proper draining of the water and prevent leaking.

Add sealant to all sides of your unit

If there remains space between your AC and the window it is installed in, leakage may occur. So, sealing those spaces with sealant can help stop the leaking.

Maintaining refrigerant level

Since a low refrigerant level causes the evaporator coil to freeze and consequently leak, it is necessary to keep the refrigerant level in check and up it when required.

Switch to a better unit

If you’ve tried everything and your AC is still leaking, you might need to switch your unit completely.

It is better to opt for a better and more practical unit than your existing one.

It is, however, always better to be safe than sorry. Many often have to pay a hefty price to get their ACs repaired.

So, it is better to take care of your unit and check up on the troublesome parts regularly before they start acting up.

Change the air filters monthly if not weekly and make sure not to overuse your appliance.

Follow the instructions of use and you should be good to go.

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Now that you know the answer to your question – why is my window AC leaking water?
You can easily take the necessary steps accordingly and fix the leakage.

While finding out the source of the leakage yourself is a praiseworthy step, we do not recommend trying to fix the issue yourself. It poses many risks, and trying to fix the leakage with inexperience will only add to the danger.

The manufacturer of your AC is usually the one you should call for help. If you find issues with your AC within the guaranteed time of customer service, you might even get your AC fixed free of cost.

We also recommend refraining from delaying the repair of your air conditioner as prolonged water leakage can lead to more severe and irreversible damage to your appliance.


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