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Why Does My Car Leak Water When The AC Is On?

why does my car leak water when the ac is on

Why Does My Car Leak Water When The AC Is On?

Have you ever noticed that your car leaks water when the AC is on? This can be a confusing issue for car owners, and it’s important to understand why your car is leaking water and what you should do about it.

Seeing water leaking from your car can be worrying, but the good news is that it is usually harmless and can easily be addressed. The most common cause of water leaking from a car when the AC is on is condensation. Cold air passes over a collection of coils when the air conditioner runs. This causes the moisture in the air to condense and form droplets of water that collect on the coils and drip from them. This natural process does not indicate a major problem with your car or its AC system.

There are a few other potential causes of a water leak in your car. This article will cover the most common causes and how to troubleshoot them.

Condensation Build-Up

condensation car ac
Photo by: Wikimedia Commons

The first and most likely cause for a leak when your AC is on is condensation build-up inside the system itself. As warm air passes through the AC unit, it will cool down and become saturated with moisture as droplets form on the inner walls of the cooling system. This moisture will then condense and drip out onto the ground below.

The good news is that this type of leak is completely normal and should not cause alarm. However, to reduce the amount of condensation that builds up, keep the air conditioner on for shorter intervals and lower the temperature setting.

Blockage In Drain Tubes

air con
Photo by: Pixabay

Another reason your car might leak water when the AC is on could be a blockage in its drain tubes. Over time, these tubes can get clogged with debris, such as leaves or dirt, preventing water from draining properly from your vehicle’s cooling system.

Fortunately, this issue is relatively easy to fix; inspect your vehicle’s drain tubes for any signs of blockage and remove any debris causing them to become blocked.  

Drain Pipe Disconnected From Ventilation System

ac pipe disconnected
Photo by: Wikimedia Commons

Another common cause for an AC-related car leak is if the drain pipe becomes disconnected from the ventilation system. This can happen over time due to wear and tear or even accidental damage caused by careless mechanics or DIYers during repair work.

If the pipe is disconnected, then water will not be able to drain properly and will instead accumulate inside the car and eventually start leaking out. This is a simple fix and can be easily remedied by simply reconnecting the drain pipe to the ventilation system. 

Low Refrigerant Level

car ac refrigerant
Photo by: Unsplash

When the refrigerant level in your car’s AC system is low, it will leak out of the condenser. This can cause water to accumulate under your car if there are no seals or gaskets. You may also notice that your AC isn’t working as well as before and that it takes longer for your car to cool down when you turn on the AC.

The best way to fix this issue is by having a certified technician check the refrigerant level and recharge or replace the system, if necessary. 

Clogged Air Filter

car air filter
Photo by: Pixabay

The air filter in your car helps keep dirt and debris from entering your vehicle’s cabin. However, over time, these particles can build up and clog the filter, which prevents air from flowing properly through the system. When this happens, moisture can collect inside the air filter and eventually cause water to drip from underneath your car when you turn on the AC.

The solution here is to inspect, clean, or replace your air filters. 

Damages Drain Tubes

damaged tubes
Photo by: Pixabay

The evaporator core in your vehicle’s AC system collects moisture as warm air passes over it during operation. This moisture then travels down drain tubes – usually located near either side of your engine bay – and drips out into puddles beneath your car when you turn on the AC.

If one or both of these tubes are damaged or blocked in any way, they can cause water to back up inside them until they overflow, leading to leaks under your vehicle while running the AC. You will need to access these drain tubes and repair or replace them to fix this issue.  

Damaged Condensate Pan

car air conditioner
Photo By: Pexels

The condensate pan is underneath your vehicle’s dashboard and collects moisture from the air-conditioning system. Over time, this pan can become cracked or broken due to wear and tear. This can cause water to leak out of your vehicle’s vents when the AC is running.

Fortunately, replacing a damaged condensate pan is relatively easy and inexpensive. You can purchase one from your local auto parts store and install it with the help of a qualified mechanic.

Faulty Seals On The Ventilation System

car air con
Photo by: Pixabay

Another possible cause of AC leaks in your vehicle is faulty seals in the ventilation system. When these seals fail, they allow moisture to escape through gaps around the vents and windows, resulting in water leakage when the AC is on.

Replacing worn or damaged seals requires some technical know-how but can usually be done relatively quickly and affordably by an experienced mechanic or technician. 


Are Car AC Leaks Expensive?

Car AC leaks can be relatively inexpensive to fix, depending on the cause of the leak. Many simple issues require only a few dollars for parts and a few minutes of labor. However, in some cases, the cause of the leak may be more complex or require more extensive work and, therefore, will be more expensive to repair.

Can I Fix a Car AC Leak On My Own?

Depending on the cause of the leak and your level of technical expertise, you can fix a car AC leak on your own. However, it is always best to consult a qualified mechanic or technician to ensure the job is done properly and safely. There are plenty of resources online that can provide you with more information.

Is AC Leaking An Emergency?

No, AC leaking is not usually an emergency. However, you should address it as soon as possible to avoid costly repairs or damage. If you notice any leaks in your car’s AC system, contact a qualified mechanic or technician as soon as possible. If you live in a hot climate, it is especially important to act quickly.

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