How To Fix Air Conditioner Leaking Water Inside

Air conditioners are a great way to cool your home during the hot summer. However, it can be frustrating when you find that your air conditioner is leaking water inside. Understanding why this happens and how to fix it can save you from potential damage to your home and costly repairs. In this article, we will explore the common causes of an air conditioner leaking water inside and provide you with step-by-step solutions to fix it.

Why does an air conditioner leak water inside?

Air conditioners are crafted to remove moisture from the air, which helps to reduce humidity and create a comfortable indoor environment. However, when an air conditioner leaks water inside, it indicates a problem with the system. There are several reasons why this may occur, including clogged drain lines, a damaged condensate pump, or improper installation. Understanding the signs of an air conditioner leaking water inside is crucial to address the issue promptly.

Signs of an air conditioner leaking water inside

Identifying the signs of an air conditioner leaking water inside is crucial for timely intervention. Some common signs include:

  1. Water stains or dampness on walls, ceilings, or floors near the air conditioner.
  2. Puddles of water forming near the air conditioner.
  3. Musty smells or the development of mold near the air conditioner.
  4. Reduced cooling efficiency or increased humidity levels in the room.

If you spot any of these indicators, it’s crucial to promptly deal with the problem to prevent additional damage to your home and maintain the longevity of your air conditioner.

Common causes of an air conditioner leaking water inside

An air conditioner passes warm air over evaporator coils, which cools the air. As cool air holds less moisture than warm air, the excess moisture condenses and becomes water. This process is similar to how rain forms. In some units, the water is directed through a tube to the outside of the housing. In others, the blower propels the water against the compressor to cool it. The water eventually collects in a pan at the bottom in both cases.

If water is dripping from an indoor AC unit, it may be due to one of the following reasons:

  • Blocked drainage tube: Dust in the air can mix with water and form a blockage.
  • Damaged drain pan: A damaged pan can lead to leaks, while a blocked outlet can cause water to overflow.
  • Incorrect tilt of the drain pan: The pan should tilt towards the outside. Some window AC units are designed to tilt the pan correctly when installed level. Units without this feature need to be tilted during installation. If the unit wasn’t leveled properly, it may have been leaking since it was first installed.
  • Dirty air filter: The dirty filter restricts air circulation around the evaporator coils, preventing the refrigerant from absorbing heat. This can lead the coils to ice over and drip water when the unit is not running.
  • Refrigerant leak: A leak can also result in the coils icing over and dripping when the unit is not in operation, necessitating professional repair.

How To Fix Air Conditioner Leaking Water Inside

If your window air conditioner needs repairs requiring access to the outdoor unit, it can be tricky if installed on an upper floor or in a tall building. If reaching it through the window isn’t feasible, you may have to bring it indoors. If that’s not something you’re comfortable doing, it’s best to seek help from a professional.

Tools and Materials

Before diving into the different solutions, gathering the necessary tools and materials is important. Here are some items you may need:

  1. Kitchen sponge: Used for cleaning the air filter and removing any debris.
  2. Screwdriver: Required for accessing and clearing the drain hole.
  3. Epoxy putty: Useful for patching any holes in the drain pan.
  4. Torpedo level: Used to check and adjust the tilt of the air conditioner.
  5. Shims: Thin pieces of wood or plastic that can be used to adjust the tilt of the AC unit.

Now that you have the necessary tools let’s look at the steps to fix an AC that leaks water inside.

Clean or Replace the Air Filter

One of the most common causes of an air conditioner leaking water inside is a dirty or clogged air filter. When the filter becomes blocked with dust and debris, it restricts airflow and causes the evaporator coils to freeze. As a result, when the ice melts, it can lead to water leakage. To fix this issue, follow these steps:

  1. Turn off the AC unit and unplug it from the power source.
  2. Find the air filter, typically situated behind a removable panel at the front of the unit.
  3. Take out the air filter from its housing and examine it for dirt and debris.
  4. If the filter is washable, run water through it while gently scrubbing with a sponge to remove accumulated dirt.
  5. Let the filter dry fully before reinserting it into the unit.
  6. Plug in the AC unit and turn it on to see if the problem persists. If the coils start icing over again, contact a technician to recharge the refrigerant.

Regularly cleaning the air filter every few months can prevent water leakage and ensure optimal air conditioner performance.

Clear the Drain Hole

Another common cause of water leakage inside an air conditioner is a blocked drain hole in the unit’s drain pan. This can happen due to the accumulation of dirt, debris, or algae over time. To clear the drain hole, follow these steps:

  1. Pull back or remove the skirting on one side of the window unit to access the area where the drain pan is located.
  2. Reach through the opening and remove any debris blocking the drain hole.
  3. Use a screwdriver to carefully poke through the blocked hole and open it up.
  4. Once the drain hole is clear, check if the water leakage issue has been resolved.

Clearing the drain hole is a relatively simple and effective solution for fixing an air conditioner that is leaking water inside.

Patch or Replace the Drain Pan

If you notice water dripping from the drain pan of your older AC unit, it likely indicates that the pan is rusted and needs replacing. However, if only one hole is accessible, you can attempt to patch it using epoxy putty. Follow these steps:

  1. Clean the area around the hole in the drain pan to ensure proper adhesion of the epoxy putty.
  2. Knead the epoxy putty until it becomes pliable, and then apply it to the hole, covering it completely.
  3. Smooth the putty with your fingers or a putty knife to create a watertight seal.
  4. Allow the epoxy putty to cure according to the manufacturer’s instructions.
  5. Once the putty is fully cured, check if the water leakage has stopped. If the problem persists, it may be necessary to replace the drain pan entirely.

Patching the drain pan can be a temporary fix, but replacing it is often the more permanent solution to prevent further water leakage.

Clean the Drain Tube

In some cases, the drain tube that carries condensate from the evaporator coils to the outside housing can become blocked, leading to water leakage inside the air conditioner. To clean the drain tube, follow these steps:

  1. Refer to your owner’s manual to locate the drain tube, as its location can vary based on the make and model of your AC unit.
  2. Use a long, thin object like a sewing needle to carefully clean the blockage from the drain tube.
  3. Remove the outside housing cover to gain better access to the drain tube. This may require opening the window or bringing the unit indoors.
  4. After clearing the blockage, reassemble the unit and verify if the water leakage has stopped.

Regular maintenance of the drain tube can prevent water buildup and ensure proper drainage, reducing the risk of water leakage.

Adjust the Tilt

If you have recently installed a window air conditioner and notice water leaking onto the floor, it is likely due to inadequate tilt towards the outside. Adjusting the tilt of the unit can help redirect the condensate outside instead of inside your home. Follow these steps:

  1. Consult the manual with your air conditioner to ensure the drain pan is installed inside the unit at the correct angle.
  2. If the pan is correctly positioned, check if the air conditioner is level in the window using a torpedo level.
  3. If the air conditioner requires outward tilting, elevate the front using thin pieces of wood or plastic until a quarter of the bubble crosses the centering line on the level.
  4. Once the tilt is adjusted, run the AC unit and monitor if the water leakage has been resolved.

Ensuring the proper tilt of your window air conditioner can significantly reduce the chance of water leaking inside.

Troubleshooting Tips for Fixing an Air Conditioner Leak

In some cases, the source of the air conditioner leak may not be immediately apparent, or the issue may persist even after attempting the above steps. Here are some troubleshooting tips to help you further address the problem:

  1. Inspect the insulation: Check the insulation around the air conditioner unit and the refrigerant lines. Damaged or inadequate insulation can cause condensation, leading to water leakage. Replace or reinforce the insulation as needed.
  2. Ensure proper drain line slope: The condensate drain line should have a slight slope to allow proper drainage. Adjust it if it is not sloped correctly to prevent water from backing up.
  3. Clear obstructions near the outdoor unit: Ensure no obstructions, such as vegetation or debris, are near the outdoor unit. These can impede airflow and cause the evaporator coil to freeze, resulting in water leakage.
  4. Check for refrigerant leaks: Insufficient refrigerant levels can result in the freezing of the evaporator coil and subsequent water leakage. If you suspect a refrigerant leak, it’s best to consult a professional for repair.

Preventing Future Leaks in Your Air Conditioner

Taking preventive measures can decrease the likelihood of water leaking from your air conditioner inside your home. Here are some tips to prevent future leaks:

  1. Regular maintenance: Arrange regular maintenance for your air conditioner, which should include cleaning or replacing air filters, examining the drain line, and checking for any indications of damage or blockage.
  2. Keep the area around the air conditioner clean: Ensure the area around the unit is free from dirt, leaves, and debris that can obstruct airflow or cause water to accumulate.
  3. Monitor humidity levels: Use a dehumidifier in rooms with high humidity levels to reduce the workload on the air conditioner and prevent excessive condensation.
  4. Install a condensate pump: If your air conditioner is located in a basement or area below ground level, installing a condensate pump can help ensure proper condensate water drainage.

Following these preventive measures, you can maintain a leak-free air conditioner and enjoy a comfortable indoor environment.

When to Call a Professional for Help with an Air Conditioner Leak

While some air conditioner leaks can be resolved through DIY methods, there are instances when it’s best to seek professional assistance. Consider calling a professional if:

  1. The source of the leak is not apparent or difficult to access.
  2. The air conditioner continues to leak after attempting the recommended troubleshooting steps.
  3. The leak is severe or causing significant damage to your home.
  4. You are unsure about performing repairs or lack the necessary tools or expertise.

An experienced HVAC technician can precisely diagnose the problem, carry out essential repairs, and guarantee the effective operation of your air conditioner.

DIY vs. professional solutions for fixing an air conditioner leak

Whether to tackle an air conditioner leak as a DIY project or seek professional help depends on various factors. DIY solutions are suitable for minor leaks that can be easily identified and resolved using basic tools and knowledge. However, if the leak is persistent, complex, or potentially hazardous, it’s advisable to consult a professional. They have the expertise, experience, and specialized equipment to handle more challenging repairs and ensure long-term solutions.

Maintenance tips to keep your air conditioner from leaking water inside

Regular maintenance is essential for preventing air conditioner leaks and ensuring peak performance. Here are some maintenance tips to keep your air conditioner from leaking water inside:

  1. Clean or replace air filters: Blocked air filters limit airflow and may result in evaporator coil freezing. Clean or replace the filters every one to three months, based on usage.
  2. Inspect and clean the condensate drain line: Frequently check the condensate drain line for any indications of blockage or accumulation. Use a wet/dry vacuum to eliminate debris or algae.
  3. Check the drain pan: Inspect the drain pan for any cracks, damage, or misalignment. Repairing or replacing it is important to ensure proper collection and drainage of condensate water.
  4. Keep the outdoor unit clean: Regularly remove any vegetation, leaves, or debris from the outdoor unit to maintain proper airflow and prevent the evaporator coil from freezing.
  5. Schedule professional maintenance: Consider scheduling annual maintenance with a professional HVAC technician. They can completely inspect the system and identify any potential issues before they escalate.

By following these maintenance tricks and tips, you can proactively prevent air conditioner leaks and prolong the lifespan of your cooling system.


Can I fix a leaking air conditioner myself?

Depending on the cause of the leak, you may be able to fix it yourself. However, consulting a professional HVAC technician for complex issues or if you are unsure of the necessary repairs is recommended.

How often should I clean the air conditioner coils?

It is recommended that the air conditioner coils be cleaned at least once a year, preferably before the start of the cooling season. However, more frequent cleaning may be necessary if you live in a dusty or high-pollution area.

What should I do if the condensate pump is not working?

If the condensate pump isn’t functioning, you can attempt cleaning it and confirming it has power. If the problem persists, it’s advisable to reach out to a professional HVAC technician for thorough inspection and repair.

Can a clogged air filter cause water leakage?

A blocked air filter can limit airflow, resulting in the freezing of the evaporator coil, which can then cause water leakage. Consistently replacing or cleaning the air filter can mitigate this problem.

How can I tell if the air conditioner has low refrigerant levels?

If your air conditioner is not cooling effectively, has weak airflow, or notices ice forming on the refrigerant lines, it may indicate low refrigerant levels. Contacting a professional HVAC technician to diagnose and address this issue is best.

Conclusion: Enjoying a Leak-Free Air Conditioner

Dealing with an air conditioner leaking water inside can be frustrating, but with the right knowledge and solutions, you can fix the issue and prevent future leaks. You can enjoy a leak-free air conditioner and a cool, comfortable home by understanding the common causes of leaks, following the step-by-step solutions, and implementing regular maintenance. If you’re unsure or uncomfortable with performing the repairs, don’t hesitate to call a professional for assistance. With adequate care and attention, your air conditioner will provide you with cool and dry air for many years.

If you’re in need of moving and storage services, consider hiring SecureSpace. With their expertise and commitment to customer satisfaction, SecureSpace can help you with all your moving and storage needs. Contact them today to learn more about their services and how they can assist you.

Storage Unit Size Guides

5×5 Storage Unit Guide

5×10 Storage Unit Guide

10×10 Storage Unit Guide

10×15 Storage Unit Guide

10×20 Storage Unit Guide

10×25 Storage Unit Guide

10×30 Storage Unit Guide

New SecureSpace Self Storage Facilities

Checkout Some Of Our Teams Favorite Articles

SecureSpace Self Storage