Car Air Conditioning Repair: 5 Reasons Why Your Vehicle’s AC Leaks Water

1. Blockage in the Condensate Drain Pipe

A warning sign that your car’s condensate drain might be blocked is when you notice water leaking inside your vehicle. If you find your car’s floor getting wet whenever you turn the air conditioner on, it’s a good indication that air conditioning repair may be necessary. A blocked condensate drain prevents water from draining outside your vehicle properly, causing it to overflow into the cabin instead. Prompt air conditioning repair can resolve the issue and prevent further interior damage or mould growth.

How to solve this?

Unblocking a condensate drain is usually easy to do, as long as you are familiar with your car’s parts and engine. First, you need to find the condensate drain hose, which is usually located at the rear of the engine on the passenger side.

When you’ve located the drain hose, squeeze or bend it gently to release any debris trapped inside. You may also carefully insert a screwdriver to help clear the blockage. Be very cautious when doing this to avoid damaging any components of the ventilation system. If you’re unsure or uncomfortable handling this task, it’s best to consult a professional who specialises in air conditioning repair. Attempting DIY fixes without the proper knowledge could lead to more serious issues that require extensive air conditioning repair later on.

2. The Condensate Drain is Not Properly Attached to the Ventilation System

Another possible reason why your car’s air conditioner is leaking water inside your vehicle is because the condensate drain is not properly attached to the ventilation system. This prevents the drain from doing its job of draining the water outside, under the car. In such cases, air conditioning repair may be needed to reattach or replace the faulty drain connection.

How to solve this?

If you are familiar with your vehicle’s parts and if you’re okay to get your hands dirty, you may try to solve this on your own.

First, you need to locate the condensate drain, which can be found under the evaporator (the evaporator is usually located inside the passenger compartment) and at the lowest point in your vehicle’s ventilation system. Attach the condensate drain properly to the ventilation system and check if it runs outside your vehicle. If you’re unsure or suspect damage, this step may require professional air conditioning repair to ensure everything is correctly connected and functioning as it should.

If you’re in doubt, it’s best to consult a professional technician.

3. Low Refrigerant Level

Your vehicle’s AC needs a certain amount of refrigerant to maintain its capability of circulating cool air. When the refrigerant level of your car’s air conditioning system becomes low, it will decrease the pressure on your AC system. Lower pressure can cause the evaporator coils to ice up and freeze, which may lead the condensate drain pan to overflow and leak water. In such cases, prompt air conditioning repair is recommended to restore proper function and prevent further issues.

For more information on evaporator coils, read our article on “The five most common causes of car air-conditioning failure“.  

How to solve this?

One of the signs that your car air conditioning system is low on refrigerant is that it blows warm air instead of cool. It’s best to have your car AC system serviced so the refrigerant levels can be checked properly and refilled as needed. Having it serviced by auto professionals is essential for a task like this, as it may require expert air conditioning repair to restore proper cooling performance.

4. Dirty or Blocked Air Filters

Over time, your auto AC’s air filter will accumulate dirt due to dust and moisture. This is the reason why it’s important to have your car’s air conditioning checked and serviced at least once a year to keep the air filters clean. 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 to solve this?

Keeping your car’s air filter clean is necessary, and this is best left to the hands of the professionals. Have your vehicle checked and serviced at least once a year, or as recommended by the manufacturer as stated in your owner’s manual. Regular AC servicing will help prevent more serious problems. After all, prevention is better than cure.

5. Broken Condensate Drain Pan

Over time, your car’s condensate drain pan may rust, crack, or break due to age, general wear and tear, or even accidental impact. When the drain pan is damaged, it can no longer collect and channel moisture effectively, causing water to leak from the air conditioning system. Left unaddressed, this issue can lead to interior water damage or even mould growth. To avoid further complications, it’s essential to seek prompt air conditioning repair. A qualified technician can inspect the drain pan, replace it if necessary, and ensure your vehicle’s AC system is operating efficiently once again.

How to solve this?

Depending on how serious the damage is, a broken condensate drain pan really should be replaced. Have this checked by an auto repair professional and replace when necessary.