The water under the car is normal when AC is on. However, water leakage inside the car indicates the following issues,
- Loose condensate drain pipe
- Clogged condensate pipe
- Broken drain pan
- Blocked air filter
- Low refrigerant
- Faulty evaporator
Don’t worry, as none of these poses anything serious. In fact, you can fix a few problems on your own.
You’ll learn details on each condition and how to deal with it in the article below.

Is Water Leaking from Car with Turned On AC Normal?
I am sure you have noticed a water pool under your vehicle during hot summer days. Of course, you run the air conditioning in full swing on those days. So, you face more water under the car than regular.
But where’s the water coming from?
Let’s take a brief walk inside the car air conditioning system to investigate the water source. Don’t worry. I will explain it in simple words.
See, the freon circulation basically does the magic of dropping the heat inside the car. As the freon circulates, you enjoy the cool air coming from the vent.
Here, the system removes humidity from the air to ensure the chill. Now, the pulled-off moisture goes to the evaporator core, where it is condensed into water.
As a result, you experience the water stream outside the car. However, you may have a problem if the water drips excessively. Such a situation indicates a faulty air conditioning system.
Also, sometimes you might mistake water for coolant and fuel. Though water dripping is normal, oil or coolant leak isn’t.
Let’s focus on the former issue for this article.
Water Leaking from Car When AC Is On: Causes & Fixes
Running AC in full swing during the summer causes water drips outside the car. But what if water leaks inside your car? You definitely have to take action to stop this.
I have pointed out 7 reasons why water leaks on AC are On and their solutions.
1. Loose Condensate Drain Pipe Connection

Examine the fitting between the condensate drain pipe and the ventilation system if you face a water leakage. The chances are that there is a loose connection between these two. As a result, the water drains inside your car floor.
Magic Fix
With a tool kit near hand, you can secure the loose connection all by yourself. But first, look for the condensate drain pipe.
In most cars, the pipe is located at the lower point of the ventilation system, under the evaporator. However, the position may deviate a little depending on the car model.
Now attach the condensate pipe with the ventilation system properly. Tighten the connection if needed.
2. The System Condensate Drain Pipe Is Clogged

By now, you know that your car’s air conditioning drips water by default. Here, the condensate drain pipe is installed in your car to channel the water flow outside the car.
However, a clogged condensate drain pipe fails to channel the water outside the vehicle. So now, you get water sloshing around in your dashboard.
Magic Fix
You can only get rid of the puddle by unblocking the drain pipe. It is a cup of tea if you know the ins and outs of car parts.
Well, don’t worry if you are not a master of the car system. The condensate drain pipe is generally set up at the back end of the passenger seats.
People often recommend using a drain cleaner to unclog the pipe. But hey! That damage the vehicle in the long run. So, why not go by the traditional method?
Here is how you can unclog your air conditioning condensate drain pipe,
Get Your Car Ready: Start by parking your car on a flat surface and switch to emergency brake mode. Use a jack to raise the car.
Collect A Metal Wire: We will use the metal wire to pull out the debris or dirt inside the pipe. So, take a 1-foot wire and make a hook at one end.
Into the Hose: Slide underneath your car and detach the pipe. Now you can easily clean this rubber hose.
Unclog the Pipe: Insert the metal wire to grab the buildups. You may have to push and twist the wire to remove the clog. But in any case, do not force the wire inside the hose.
Reattach the System: Water will drain from the pipe once the buildup is removed. Set up the hose properly, and lower your car from the jack. Now your car is ready for a splash less drive.
3. Useless Condensate Pan

Water dripping from the coils accumulates in the condensate pan first. Then it flows out of the vehicle. So, any damage to the pan causes water leakage in the car.
The condensate drain pan can get broken due to an accident. But in most cases, rust or wear causes damage.
Magic Fix
In some cases, it may be possible to repair the condensate pan. However, replacing the old pan with a new one is always recommended.
4. A Blocked Evaporator
The evaporator core has an open structure. Therefore, dirt and debris can get inside, blocking the system. A clogged evaporator often prevents water from draining outside and channels it back to the core.
Water from the core may also get inside the AC vents. Hence, you notice the water dripping.
Magic Fix
The evaporator core requires cleaning if it is clogged. Taking the car to a garage is the easiest way to deal with this water leakage.
5. Running Out of Refrigerant

In car air conditioning systems, freon is used as a refrigerant. The gas ensures smooth circulation of cool air inside your vehicle.
Though the refrigerant does not leak, it needs refilling every three years. Otherwise, the freon level will drop, decreasing the pressure on the air conditioner system.
The fallen pressure ices up the evaporator coil; on the heating cycle, the frozen gases will convert into liquid, overflowing the condensate pan. Therefore, you notice the water puddle in your car.
Magic Fix
You cannot solve the air conditioning issue yourself unless you are a professional. So, call your mechanic and get the servicing done.
Other than the water dripping, there are some other signs indicating the low freon issue:
- The AC will not work as per expectations. It will circulate warm air instead of chilly air.
- Generally, turning on the AC involves a click sound, indicating that the system clutch is engaged. However, the clutch can not fit on the system when the refrigerant pressure is low. Hence, no more click-like noise.
- A Freon leak is uncommon but not unexpected. You may notice these thin greasy substances under your vehicle or compressor hood. The visible Freon leak also causes a low refrigerant level.
6. You Haven’t Cleaned the Air Filters in Years

Of course, our air is not pure and dust-free. So, when the air conditioners suck up room air, the dust also gets into the system. Therefore, an air filter is installed on the system to keep the unwanted elements out.
No wonder why the air filter gets dirty so frequently. However, not cleaning the filter is definitely not a good idea. It can block the filter, freezing the evaporator coil.
Consequently, the iced-up coils drip water from the condensate pipe, creating a puddle in your car.
Magic Fix
Regular air conditioner servicing is the best way to prevent this water leakage. Again, a routine air filter cleaning at least once a year will also keep the area clean. In any case, leave the situation to the professionals.
7. Damaged AC Seals
The AC is packed with plastic and rubber seals to back up the system. Any damage, corrosion, wear and tear in those linings or seals can cause water leakage.
Magic Fix
There is no way of telling whether the AC seals are broken. So, call your mechanic to take a closer look into the system. You may need to replace the seals if they are damaged.
Frequently Asked Questions
Is it normal for ac to leak a lot of water?
The car air conditioning system can drip water outside the vehicle. But if you notice water leakage inside the dashboard, something is fishy in the system. However, turn the AC off if there is excessive water flow.
Why is my car leaking water inside the driver’s side?
A clogged air conditioner drain pipe is one of the reasons why there is water on the driver’s side. The other causes are faulty heat exchangers, damaged door seals, etc.
Conclusion
Why is water leaking from my car when AC is on? The chances are your condensate drain pipe system is broken or blocked. If not, look into the evaporator core and refrigerant level to detect the problem.
Sometimes a damaged seal inside the AC or broken air conditioning also leads to water dripping inside the car.
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