Why Is My Air Conditioner Leaking Water?

One of the most common AC problems homeowners experience is an AC leaking water. After using your AC to cool your home on a hot summer day, you may see water damage on the floor. And upon close inspection, you notice the water is coming from the AC. Why does it leak? And most importantly, how can you stop the leak?  

Is Water Leaking From Air Conditioner Dangerous?

Yes, water leaking from your air conditioner can be dangerous. An AC unit leaking water can be a much more serious problem than a few drops or a puddle of water on the floor. Water leaks can cause major water damage to your home and belongings, and in most cases, they are an indication that something is wrong with your air conditioner.

While an air conditioning unit leaking water is generally easy to fix, if ignored it can result in damage to your home’s walls, floors, or electrical systems and even lead to dangerous mold growth.

Before calling an HVAC professional, you may want to check the system to see if the cause is something you can fix yourself. Most HVAC systems leak for the same reasons. And there’s a common solution to most of those problems. 

11 Reasons Why Your AC Is Leaking Water

HVAC systems vary by model, however, they all function the same way and therefore have similar problems. During the dehumidifying process, your air conditioner creates condensation, but under no circumstances should this water be leaking out of your vents or AC unit. Below are some of the most common reasons why your AC is leaking water.

1. Clogged AC Drain Line

Most often, your air conditioner is leaking because your drain line is clogged. When the drain line clogs, it causes the air conditioner’s drain pan to overflow, which causes the condensation produced by the air conditioner to leak out of the unit. Drain lines often become clogged with algae, dirt, and other debris, so it’s important to clean your AC drain line frequently to avoid leaks.

The AC system produces water as part of the cooling process. It takes warm air from the room and passes it to the pipes containing refrigerant. The cold refrigerant cools the air, which condenses into water. Then the water drains through a hose pipe that takes it outside the house.

If the pipe has debris or dirt stuck inside, the water starts to drain slowly, leading to an overflow. Sometimes the hose can block completely, making the water spill back into the house.

Solution: Unclog and clean your AC drain line.

2. Damaged Drain Overflow Pan

It’s possible that your drain line is working as intended, but the problem is with your drain pan. Check your AC’s drain pan for cracks or leaks. To do this, pour about a gallon of water directly into the drain pan and watch how the water drains. If the water leaks out of the drain pan instead of going down the drain line, then the problem is with your drain pan.

Solution: Small cracks and leaks can be patched, but oftentimes it’s best to replace the condensate drain pan instead of trying to patch the leaks.

3. Disconnected AC Drain Line

Sometimes, air conditioning systems are not installed properly. If the drain line is not connected correctly, it may start to loosen over time. If the drain line disconnects from the unit, the condensation it produces will just leak onto the floor.

Solution: Follow the drain line from your AC unit and check for any disconnected PVC pipes. If you follow the pipes to the outside and see water dripping, this isn’t your issue. If you don’t see water dripping and you are sure there isn’t a clog, then the drain line may have disconnected somewhere along the line.

4. Broken Condensate Pump

A broken or dirty condensate pump can also cause your air conditioning unit to leak. The condensate pump is used to remove the condensation created by your AC system. If the pump is not working, it could be a problem with either the power to the pump, the motor, or the pump itself. Since an air conditioning unit continually produces condensation, this can cause the pump to become clogged with mold or mildew, so it is important to make sure that you clean it often to avoid these issues.

Solution: Clean your condensate pump. If that doesn’t fix your issue, you can try replacing the condensate pump or consult an HVAC professional to help.

5. Clogged Air Filter

When is the last time you changed your AC’s air filter? Air filters are by far the most neglected part of an AC system even though they’re an essential component. If your air filter is dirty enough, it can clog and prevent airflow, which will have a domino effect and could cause your AC system to leak water. When the air filter gets too dirty your AC has to work harder to cool the house. As a result, the evaporator coil becomes too cold and ices over. Then as the ice melts, it causes water to overflow on the pan and spill into the house.

A good rule of thumb is to change your air filter each month to get the most out of your air conditioning system.

Solution: Replace your AC’s air filter.

6. Refrigerant Leak

Refrigerant is used to cool the air that is pumped through your home, so when refrigerant levels get low from a refrigerant leak or other issue, your system will not operate as it normally would. If you notice that your AC system turns on and off repeatedly, this could be a sign of a leak.

Solution: If you suspect this is the case, contact an HVAC professional immediately. Refrigerant leaks can be dangerous and require a certified technician to fix them.

7. Air Duct Leaks

Ductwork is important to your HVAC system. Your air ducts must be maintained just like the rest of your home. If air is leaking from your ducts then the warm and cold air can mix and produce condensation.

Solution: Check your ductwork for air leaks and patch any holes you find.

8. Lack of Preventive AC Maintenance

An AC tune-up and preventive maintenance check will prevent clogged drains and related water leaks. Cleaning your drain pan and drain lines will enable you to make it through the summer without having to worry about flooded areas in your home. Additionally, cleaning the coils and other parts of your AC system can improve the efficiency of your system. Worn parts can be identified before fail and lead to problems, allowing you to know that your equipment is ready for the hot summer.

Solution: Perform routine AC maintenance or contact an HVAC company to do this for you.

9. Improper HVAC Installation

An AC unit needs to be on a flat surface. Otherwise, water can overflow on the pan and spill from the sides. Window air conditioners require tilting towards the drain hose. If the AC tilts in the wrong direction, it can spill water into the house. That said, you can always make adjustments to restore it to the correct position.

Solution: Inspect your AC to make sure it’s on a flat surface or if it’s a window AC, make sure it’s tilted the correct way.

11. Improper Filter Fit

When you replace your air filter each month be sure it is installed properly into your system. If the filter isn’t properly installed then it could lead to a malfunction in the system, causing leaks and other issues.

Solution: Check your AC filter and make sure it’s the proper size, fits snug, and is facing the right direction.

11. Problem with the Pump

If your AC system is in the basement, you can’t rely on gravity to drain the water from the overflow pan. That’s why ACs have pumps. These tools help drain the water where gravity can’t work. If the pump isn’t working, the water remains on the pan and spills into the house.

Solution: If you followed all the steps above and couldn’t find any issues, call an HVAC professional to inspect your AC.

What to Do If Your AC is Leaking Water

If your AC is leaking due to one of these reasons, here’s what you can do.

Step 1. Turn Off the AC

Once you notice water leakage from your AC, turn the system off. It’s critical to do so to prevent the problem from getting worse. Before assessing the system, go to your power supply panel and flip the circuit that powers the AC. This step will protect you from electrocution if you touch the electronic parts.

Step 2. Dry the Water

Use towels or a wet/dry vacuum to dry the water from the floor. If the walls are wet, use a dehumidifier and fans to dry them. Drying up the moisture will protect your carpet and drywall from water damage. But if the water has been leaking for a while, assess whether there’s any substantial damage caused. You’ll also need to keep monitoring the walls, especially in the basement, for signs of mold.

Step 3. Inspect the AC System

AC problems can range from minor issues you can solve to major ones that need an HVAC professional. Before calling an AC expert, you can try to solve the problem if you’re a DYI person. There are multiple things you can fix yourself that could probably be causing the leak. After trying the above methods, turn on the AC and observe whether the water leak has stopped. If it hasn’t, the problem is probably beyond you. Leave the AC turned off to prevent further damage and call for professional help.

Step 4. Call an AC Professional

Despite your best effort, you may not have the required expertise to fix all problems in your AC. Here, it would be more appropriate to call someone with more skills to help. You should call a professional if:

• The AC continues to leak after cleaning or replacing the filter
• The AC leaks even after unclogging the drain pipe
• It has structural damage
• The problem keeps recurring after you fix it

Keep in mind that HVAC systems need regular maintenance from professionals to keep them performing efficiently. So ensure you schedule one inspection per year. Moreover, remember to replace your filter every 1-3 months.

How to Prevent AC Water Leaks

A continuous water leak from the AC can cause water damage to the drywalls, ceiling, and carpet. Your house can get mold due to the moist conditions. Not only will this concern lead to extra expenses in water damage restoration, but it may also cost more to repair the AC.

But then, you can prevent these problems by performing regular maintenance and regular inspections. The good news is that you can do some of the maintenance yourself, such as cleaning and replacing the filter. But if the problem is beyond your capability, call for professional help. Keep in mind that the cost of an inspection is much lower than that of repairing the AC.