What Causes Excessive Water Leaking From Car Air Conditioner?

Your car’s air conditioner (A/C) is a crucial component responsible for making the air temperature inside your car cool and warm as the weather demands. A faulty air conditioning system can cause a lot of discomfort. That’s why most folks are particular about how well their car’s air conditioner works, especially during summer or winter. This explains why you are probably worried about the excessive water leaking from your car’s air conditioner.

It is not unusual to notice water dripping under the car when the A/C is not on. However, you should be worried when the leak becomes excessive. Even at that, it might just be a minor issue or a complex one that requires professional help. You never know until you know the “why” of the situation. That is why you must understand why your air conditioner is leaking all that water. Let’s explore some of those reasons.

What Are The Reasons for Excessive Water Leaking From Car Air Conditioners?

You might experience two types of water leaks from your car A/C. The first is excessive water leaking outside the car. You might notice this water leak after the car is turned off and the reason is this. When you use your car A/C for extended periods on hot days, there is a tendency for you to find some water leaking under the car. This happens because your car is draining the excess water that builds up when the air conditioner absorbs humidity in the air to cool the vehicle.

The second type of leak occurs when water leaks inside your car. You should get professional help if you notice this. That said, here are some of the reasons for an excessive water leak from your car A/Hopefully, at the end of the article, you will have answers to the internet query “my car is leaking water but not overheating.”

water dripping under car ac not on

Problems with the Condensate Drain Pipe/Pan

A blocked condensate drain can lead to excessive water leaking into your car’s cabin whenever you turn your air conditioner on. Here is why it happens. Cooling your car’s interior requires moisture to be extracted from the air. After the cooling process, this moisture is condensed to water which your car’s condensate drain is designed to expel out of the vehicle. When the condensate drain is blocked by dirt and debris the water starts leaking into the car. Water leaking into your vehicle is one of the clogged ac drain car symptoms.

 One other reason why you might notice excessive water leaks from your car’s air conditioner is because of a poor installation of the car’s condensate drain. When the condensate drain is not well attached to the ventilation system, water leaks inside your car because it is not properly drained outside the car. It might also be an issue of the wrong size of the drainage pan being installed.

A broken condensate pan can also cause water to leak from your air conditioner, especially when rusted or cracked because of wear and tear or accidents.

Low Refrigerant

To circulate cool air within your car, your car’s A/C needs a certain level of refrigerant. Once the level of the refrigerant reduces, it decreases the car A/C pressure. This causes the evaporator coils to freeze, leading to a situation where the condensate drain pan overflows and leaks. A low refrigerant can also cause your car to give hot air.

Blocked Air Filters

As long as you use your car’s AC, the air filters will accumulate dirt and debris because of all the dust and moisture that it comes in contact with. Dirty air filters can degenerate into blocked filters that can freeze up your car’s air conditioner’s evaporator coils. When this happens, the condensate drain pan gets filled, and the excess water overflows from the drain pan. The result is an excessive water leak from the car’s air conditioner.

Problem with the Evaporator

A blocked evaporator drain can cause water to drain outside the car to back up into the evaporator core. This component looks like a radiator, and once it gets flooded, some of the moisture gets into the A/C vents. That is what happens when you notice water coming out of the A/C vents in your car.

Because of the evaporator core structure, it is easy for leaves and other biodegradable materials to get to the evaporator via the vents. After these materials have decomposed, they cause the evaporator core to rust, and after a while, it starts to leak. This leak can cause an excessive water leak from your vehicle’s air conditioning system.

Failed Seals

Your car’s air conditioning systems make use of plastic or rubber seals. Once these fail, you will find that water easily leaks through them. In such instances, you might notice water leaking inside the car passenger side for instance.

Water from AC: Leaking Under Vehicle YouTube 


Q: Is It Normal For AC To Leak Water?

Yes, it is. It is pretty standard for your car A/C to leak water from under the car. This situation often occurs on hot days when you must have been using the A/C at its highest. It happens because your car’s A/C system is designed to allow water to drain out of your vehicle. The process of cooling your vehicle requires the air conditioning system to use the humidity in the air. The residual water is then drained out of the car. You should be worried when you notice water leaking inside your car from your A/C.

Q: How Much Water Should Drain From Car Air Conditioner?

Your car A/C  drains condensed water after the cooling process of the A/C systems. A drop or two is not a cause for concern. You should be worried when you notice a puddle of water inside or outside your car.

 Q: How Do I Stop My AC Unit From Leaking Water Inside?

There are two ways you can approach a situation of water leaking inside the car from your A/C unit. You could get professional help or go about it the DIY route.

If you opt for the DIY way, your first step would be to locate the car’s condensate drain in the engine bay. For most cars, it is in the area opposite your glove box. The next step is to inspect the drain hose to see if some sticks or leaves might be blocking the flow of water. If you don’t find anything there, try checking the car’s A/C evaporator core to check for any leaks or damages to the ventilation system.

If you are not satisfied with the results you get, it might be a good idea to get some professional help. Has your car been checked by mechanics who can easily find out whatever is causing your car’s A/C unit to leak water inside your car?

Final Words

A working car A/C system is a great thing to have in your car during the summer and winter months. This is because it helps you keep the car’s interior temperature just the way you need it. Sometimes your A/C system can cause you some problems. Say, for instance, when you notice that there is excessive water leaking from your car’s air conditioner.

A situation where you find water leaking inside your car can be problematic. However, after reading this article, you should know why your car’s A/C system leaks water excessively. Get a mechanic to run checks on your car whenever you notice something like this.

Read More:

Osuagwu Solomon

Osuagwu Solomon is a certified mechanic with over a decade of experience in the mechanic garage, and he has over five years of experience in the writing industry. He started writing automotive articles to share his garage experience with car enthusiasts and armature mechanics. If he is not in the garage fixing challenging mechanical problems, he is writing automotive repair guides, buyer’s guides, and car and tools comparisons.

Leave a Reply

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

Recent Posts