Why does water come out of car when AC is on?

Author: Virginia Sawayn MD  |  Last update: Sunday, December 14, 2025

When the refrigerant level of your car's air conditioning system becomes low, it will decrease the pressure on your AC system. Lower pressure will cause the evaporator coils to ice up and freeze, and this can cause the condensate drain pan to overflow and leak water.

Is it normal for a car to leak water when the AC is on?

Many times when the vehicle's air conditioner is in use, there will be water dripping from the condenser's drain visible under the vehicle, which is perfectly normal. The window air conditioning units in the house will also allow condensed water to drip to the ground and is a natural part of the unit's operation.

How to stop AC water leakage in car?

Air Conditioning System Leaks
  1. Clear the Drain Tube: The AC system has a drain tube that can get clogged. Locate the drain tube and ensure it's clear of any obstructions.
  2. Inspect the Evaporator Core: A leaking evaporator core can cause water to accumulate inside the car.

Why does water come out when AC is on?

A clogged condensate drain line is the most common cause of water leaking from your AC into your home. If the drain line gets clogged with dust, dirt, sludge or mold, that water backs up into your home. In that case, you'll need to unclog it.

How do I fix my AC spitting water?

When the drainage system that carries water from your AC system away from your home becomes clogged with dust, dirt, and other debris, water can back up into the unit and eventually overflow, causing it to spit water. To fix this issue, you must unclog the drain line or have a professional HVAC technician do it.

Water from AC: Leaking Under Vehicle

Is it OK if water comes out of the AC?

Water leaking from your AC unit isn't dangerous, but refrigerant leaks are. Exposure to refrigerant leaks for extended periods is poisonous to your body. Air conditioners use refrigerant to turn warm air into cool air.

Should I be worried if my AC is leaking water?

Maybe you noticed a puddle of water indoors after your AC runs for an extended period of time — whichever is the case, if your air conditioner leaks water, it's important to schedule AC repair immediately.

How do I stop water from coming out of my air conditioner?

Here are 5 possible solutions to fix the issue
  1. Seal or Replace the Drain Pan. A damaged drain pan must be meticulously and firmly sealed. ...
  2. Clean the Drain Line. Additionally, you must regularly clear your drain pipe.
  3. Fix Condensation Build-Up. Condensation build-up can cause water leaks from the AC. ...
  4. Correct Installation.

Where do air conditioners drip water from a car?

Specifically, the evaporator core leaks water from under the passenger side of the engine compartment when the air conditioner is being used. This is normal use. Coolant: if the liquid smells sweet and appears to be tinted or colored (yellow/green), it could be coolant.

Is it normal for AC to drain water?

Your air conditioner should naturally drain water that was once humidity out of your home. On average, you can expect 5 to 20 gallons of condensate per day. If water is not draining, your climate may be too dry or your system is not functioning properly.

Why is my car AC producing so much water?

Dirty or Blocked Air Filters

When your AC's air filter accumulates debris, it may become blocked. This may freeze up the car air conditioner's evaporator coils, which will cause excess water to overflow from the condensate drain.

How do I know if my car AC drain is clogged?

You see water on the floorboards.

Your AC has a drain hose that directs excess moisture away from the evaporator coils and out the undercarriage. If this hose is clogged, condensation will accumulate in the unit and begin dripping into the cabin.

How much water leaking from car AC is normal?

That humidity becomes liquid, so it's natural that water should be expelled as it drains. But any water draining from your car AC should be a drip, not a waterfall! Any more than a saucer-sized patch is a concern.

Why is my car leaking water when parked?

Your car leaking water, especially near the back of the vehicle, is normally caused by air conditioning condensation or exhaust condensation. Both of these kinds of leaks are normal. Your biggest concern should be if the liquid isn't water, but there are easy ways to test that in your Arlington home.

How much does it cost to fix a leak in the car AC?

The actual leak repair depends on the component that's leaking. A simple O-ring can cost just a few dollars plus labour, but a new air conditioning line or condenser can cost hundreds of dollars. All-in, you can expect to pay $150 to $1,000 or more for a leak repair.

How much condensation from AC is normal for a car?

A drip or two of water leaking from under your car is normal, but if it is increasing in frequency and volume, your car needs to be checked.

Do all cars leak water when AC is on?

Despite the way it may look, your car leaking water from the AC is usually not serious. Whenever you activate the air conditioning, it creates a bit of condensation, which can present as a small puddle of water. If you see small puddles like these near the back of the engine compartment, that's probably the cause.

How to unclog a condensate drain?

To unclog an AC drain line, turn off the power to the unit. Locate the drain line and use a wet/dry vacuum to suck out the clog. Flush the line with water using a garden hose or cup of water. Check and clean the drain pan under the indoor unit.

Why is there a puddle of water in my car?

Your car's A/C removes heat and moisture from the cabin via an evaporator core, which is chilled using a refrigerant that rapidly absorbs heat from the air pushed across its fins by the blower motor. As the warm air passes over the cold evaporator coil, the moisture from that air condenses into water droplets.

Why is my AC bringing out water?

Clogged Condensate Drain: This is one of the most common reasons for air conditioner leaks, and it happens to be one of the easiest problems that homeowners can check for on their own. Dust, dirt, and other debris can clog the drainage system that carries water from your AC and away from your home.

How to tell if you have an AC leak in your car?

How to Tell If Your Car Air Conditioning Has a Leak
  1. Your car A/C is blowing warm air. Schedule an Appointment. ...
  2. You hear a clicking sound when your A/C is running. If you notice a clicking noise while your car A/C is running, your compressor might be short cycling. ...
  3. Your dashboard alerts you to issues.

How to check condensate drain?

Turn off the power to the air conditioner. Remove the access panel and inspect the overflow pan. Use a flashlight to inspect the drain pan and the overflow drain pan. Note any cracks, dents, holes, rust, and mold or algae build-up.

How to fix air conditioner leaking water inside car?

HOW TO FIX. First, locate the drain pan and inspect it for any cracks or breakage. After that, replace the damaged drain pan with a new one and ensure its correct installation. Practising such fixes of water leaking from the car AC will help prevent any further leaks in the car AC.

Why is my air cooler leaking water from the bottom?

Faulty Water Tank: If you notice water leaking from the bottom of the unit, it may indicate a more serious issue such as a broken tank or small holes in the unit. For minor holes, applying an elastomeric sealer can provide a temporary fix.

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