Water Leaking Inside Car When AC Is on | Causes & How to Fix

Water leaking inside a car when the AC is on may cause by several reasons. It may be the door seals are not working, maybe there is a problem in the window area or the Air conditioner. If the window area and the door seals are doing alright, then the problem is in the AC. Because of these reasons, water leaks while AC is on. Water roles under passenger seats or in the front passenger footwell or floor. It depends on the car’s model.

 If you are facing this irritating condition, then please check the following instructions. However, the process of solving this water leakage is quite simple.


Causes of Car’s AC Leaking Water

Various reasons exist for the car’s AC leakage, which means leaking water. Water leakage can occur inside the car or outside the car. Water leaking outside the car is normal. It allows for the draining of water from the vehicle. However, leaking water inside the car is an issue.

To fix this problem, it is compelled to identify the cause first. Defected seals, clogged evaporator drain, and damaged evaporator coil are the common causes of a car’s AC leakage.

1. Clogged Drain Line

An evaporator drain line passes condensation and excessive water from the car. Dirt and filth block this line more often. This creates water leakage inside the car. Excessive water gathers in the line. Then it overflows inside the passage footwell or floor.

Caution: If excessive water stays in the evaporator core for a long time, it can damage different AC components.

2. Defected Seals

Using plastic seals for a long time can damage its usefulness. Then water can drip out of the AC system, which is a cause of the wet floor. You will understand if the passenger side floor mats are wet and if you see water emerges from there.

3. Damaged Evaporator Coil

An evaporator coil helps the air conditioner absorb heat. It is placed in that part of the system. Any defect in the evaporator coil can cause water leakage.

How to Fix Water Leaking inside Car When A/C is On

Tools that you need:

  • A pair of gloves
  • A vacuum cleaner
  • New seals
  • A towel or bowl

Step-1: First, identify the problem. If it is because of the clogged drain line, then you need to clean up the drain.

Step-2: Secondly, take off the plastic cover off which is near the drain line. Without removing it, you won’t be able to clean up the drain line. Pull the cover carefully. Then take it off smoothly. Afterward, pull back the carpet from that side. Then you will see the air conditions drain line.

Step-3: Now, take a bowl or towel. If you use a towel, then put it around the drain line. You can also place a bowl near the drain line.

Step-4: Then disconnect the connection between the drain line. Excessive water will come out immediately. Do not worry; the towel will soak the water. If you used a bowl, then the water will fall in it. Shake the line gently to remove the rest of the water.

Step-5: It’s time to use a wet and dry vacuum. Connect the vacuum hose to the drain line with duck tape. You will need duck tape to connect the line and the vacuum. Hold the vacuum and put it inside the line. Then use a duck tape to rap the connection point. Tap it properly so that there exists no lick.

Step-6: Now, turn on the vacuum. It will suck out any obstacle or filth that stocks in the drain line. Then remove the vacuum from the line and put it on the discharge side. Repeat the process. If anything sticks there, the vacuum will suck it.

Step-7: After that, connect the drain tubes altogether. Then place the carpet back to its place. Finally, put the plastic cover. Press it and check whether it sticks in place or not.

Step-8: If the water is still leaking, then the problem might be in the seals. Now you have to fix the seals. Seals in the A/C system may get defective over time. To fix this problem, you need to replace the seals with new ones. For this, buy the new seals from an auto repair shop. Then pull off the old seals and attach new seals.

Step-9: If you are still facing the problem, then there is definitely a problem with the evaporator coil. Sometimes, things might get inside through air intake vents which later cause damage. 

Check the evaporator. Clean it well. If any object stocks there, then remove it. If you have seen any damage, then replace the part with the new ones. There might be a problem with the evaporation coil. Then you have to remove it and set a new evaporator coil inside the A/C.

Step-10: Finally, clean up the whole A/C. If everything goes well, then the water leaking will stop.


  • Wear a pair of gloves while working.
  • Clean the wet carpet or the floor. It will help dry the wet place quickly.

Frequently Asked Questions (FAQ)

  1. How to stop occurring leaking water?

You can stop this problem by regularly checking the drain lIne, Cleaning the evaporator often and changing the seals once in a while.

  1. Is it a serious problem?

If it is in the primary stage, then it is not a serious problem. But if it happens for a long time, then it can be. It can damage your carpet. It can damage the whole evaporator and also the drain line.

  1. When the leakage water becomes necessary to fix?

If you smell something from the evaporator, then immediately check it. It is not a good sign. You have to clean the A/C and change the damaged parts of the components.

Final Thoughts

If you are facing problems to fix water leakage inside your car while A/C is on. No need to worry anymore. This article is for all the enthusiasts out there looking for a solution for leaking water inside the car. It will help you to solve this problem on your own.

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