Leaking Ductless Air Conditioners: Causes and Solutions

air conditioner

Leaking ductless air conditioners is a common problem for many households, but there are a few things that you can do to fix the issue. Here are some of the most common causes of leaking in ductless air conditioners and what you can do to solve the problem.

1. Dirty Air Filter

One of the most common causes of leaking in ductless air conditioners is a dirty air filter. When the air filter becomes clogged with dirt and dust, it can restrict airflow and cause the unit to work harder than it needs to. This can lead to condensation on the coils, which can eventually lead to leaks.

To fix this problem, simply replace the air filter with a new one. Be sure to check the air filter monthly and replace it as needed.

2. Clogged Drain Line

Another common cause of leaking in ductless air conditioners is a clogged drain line. The drain line is responsible for draining away any condensation that forms on the coils. If the drain line becomes clogged, the condensation will have nowhere to go and will eventually start to leak.

To fix this problem, you’ll need to clear the clog from the drain line. This can usually be done with a plunger or a plumber’s snake. If the clog is severe, you may need to call a professional to clear it for you.

3. Refrigerant Leak

A refrigerant leak is another common cause of leaking in ductless air conditioners. The refrigerant is what helps to cool the air, so if there is a leak, the unit will not be able to cool the air properly. This can cause the unit to work harder than it should, which can lead to condensation and leaks.

If you suspect that your unit has a refrigerant leak, you’ll need to call a professional to have it repaired. Trying to repair a refrigerant leak yourself is dangerous and can cause further damage to the unit.

4. Faulty Installation

If your ductless air conditioner was not installed properly, it could also be the cause of the leaks. If the unit is installed too close to the wall, it can cause condensation to drip down the wall and onto the floor. If the unit wasn’t level when it was installed, it could also cause leaks.

If you’re not sure how to install your ductless air conditioner, you should call a professional to help you. Having the unit installed properly can help to prevent leaks.

5. Frozen Coil

The coil in your ductless air conditioner can freeze over time. This can happen if the unit lacks airflow or the temperature is set too low. A frozen coil can cause water to build up and leak out of the unit.

If you think that your coil is frozen, you’ll need to turn off the unit and let it thaw out. Once the coil has thawed out, you can turn the unit back on and see if the problem has been fixed.

6. Damaged Gasket

The gasket is a rubber seal that goes around the edge of the unit. This seal helps to keep the unit airtight. If the gasket is damaged, it can cause air to leak out of the unit. This can cause the unit to run less efficiently.

If you think that your gasket is damaged, you’ll need to replace it. You can buy a new gasket at most hardware stores.


Ductless air conditioners are a great way to cool your home without the hassle of ductwork. However, they can be susceptible to leaks. If you notice your unit is leaking and you notice signs of damage, contact a professional to have it repaired.

If you’re having trouble with your ductless AC, Lennox® air conditioner repairs in Toronto has the solution for you. We are a Canadian-owned and operated company providing installation, repair, and maintenance services on all major brands of furnaces and air conditioners. Trust us to provide quick and efficient services 24/7. Whenever you need some repair work for your AC unit or mini-split heater systems in Toronto, we are the ones to call. Contact us today for a free estimate!

Call Us Now For A Free Estimate 1-855-241-7171