3 Ways to Fix An Air Conditioner Leak

Few things are more annoying than living in what feels like a furnace due to a leaking air conditioner. 

The good news is, often, air conditioner leaks don’t necessarily require hiring a professional. It’s something you can do yourself.

If your AC is leaking due to a clogged drain line, using vinegar to kill fungi and algae build-up or clearing it using a wet-dry vac is the solution.

For a missing or cracked drain pan, you have to replace it.

And where the air filter is clogged, freezing up your evaporator coil, you have to change it to allow free flow of air.

Below is an outline of the steps you can follow to help solve the problem.

3 Reasons Why Your Air Conditioner Is Leaking

Here are the three main reasons your air conditioner is leaking:

1. Frozen Evaporator Coils

Once dirt builds up in your air filter, it interferes with the ease air can flow through. 

The refrigerant flows through the evaporator coils, and for it to absorb heat properly, there must be a smooth flow of air.

When airflow is restricted, the evaporator coils freeze up, and the ice forms subsequently drip excess water.

Other causes of frozen evaporator coils include:

  • Broken blower motor
  • Dirty coils
  • Lack of refrigerant
  • Blocked registers/vents

How to Fix:

Remember, once your evaporator coils freeze up, it marks the end of your refrigerant absorbing heat from your house.

The result is a home full of warm air or potentially no air at all. It may even lead to compressor problems.

As soon as you notice your evaporator coil has frozen up, turn off your AC. Turn it back on only after you resolve the issue.    

You can also avoid future problems with frozen evaporator coils by ensuring you replace your air filter every 30-90 days. At the same time, refrain from covering any registers or air vents. 

During the summer months of more active AC use, you should change your air filter more often. Calendar reminders come in handy in helping to remind you to check the air filter at the end of every month.

Clearing all your air vents and replacing your air filter should solve the problem.

Now turn the AC system on and observe whether it’s still leaking.

If the problem persists, it might be that you have a low refrigerant charge, and you have no choice but to call in a professional.

2. Clogged Condensate Drain Line

The second most likely reason your air conditioner leaks is a clogged condensate drain line. Solving the problem is easy, as long as you have the necessary tools. 

Some of the causes of a clogged drain line include algae, fungi, and debris build-up.

How to Fix:

Fixing a clogged condensate drain line is a project you can do all by yourself. But you must have a wet-dry vacuum. Follow these steps to stop the leak:

  1. Find the PVC pipe, usually located close to the air handler’s drain pan. It’s a piece of pipe sticking up at a right angle with a cap on its top.
  2. Take off the cap and pour six ounces of vinegar into the drain line. In fact, make it a habit to pour vinegar down the line every few months. Doing so kills fungi or algae buildup in your drain line.
  3. Check if you succeeded in clearing up the drain line. If it’s still clogged, you’ll have to clear the condensate line using a wet-dry vacuum.
  4. When using the wet-dry vac, first locate your outdoor condensate drain around your condenser unit. Then, connect the wet-dry attachment and turn on your vacuum. 
  5. If necessary, use a high-pressure suction pump. 
  6. Again, pour vinegar solution into the drain line and let it sit for about an hour. That will eliminate any stubborn debris.
  7. After you’re sure no debris, dust, or rust is left behind, flush the drain line with clean water starting from the top.

Granted, unclogging a drain line can be time-consuming, but it’s worth every second you spend cleaning up.

It’s important to note that most attachments sold at home improvement stores allow you to connect your wet-dry vacuum with the outdoor drain. If the attachment cannot connect properly, seek the services of an expert.

The good news is that modern AC systems come with auto shut-off switches for clogged condensate drain lines and air filters.

First, check your drain line and air filter if you notice that your air conditioner isn’t turning on. They might be clogged.

3. Missing, Cracked, or Overflowing Drain Pan

A cracked, rusted, missing, or over-full drain pan is another reason your AC is leaking. 

The drain pan rests under the indoor air handler, inside which is your evaporator coil. Any condensation from your AC unit lands in the drain pan.

How to Fix:

The first step is to turn off the air conditioning system so that you can inspect the drain pipe and pan for leaks.

Disconnect the AC as well from the power/breaker. The two are connected, with the pipe discharging condensate outdoors.

Use your wet-dry vacuum to clean the pan if it’s overflowing. Then inspect its edges, corners, and bottom with the help of a flashlight. 

You might have heard or figured out that you can use water sealant on a cracked drain pan, but that’s just a temporary solution. Solving the issue once and for all requires replacing the damaged pan with a new one.

Don’t forget that there are usually two drain pans.

One is permanently fixed underneath the evaporator coil, and the other is removable.

It’s under the AC unit. When mending the leak, the permanent drain pan must remain in position.

If you decide to replace the permanent pan, call in a professional as this primary pan is welded in place.

Otherwise, replacing a rusted, cracked, or misplaced auxiliary pan is easy. It’s a DIY project, no doubt.

How to Prevent Your Air Conditioner From Leaking

There’s much you can do to prevent your air conditioner from leaking in the first place. 

  1. Make a habit of replacing your air filter every 30-90 days to prevent clogging. Also, check the blower motor for damage regularly, clean dirty coils, and ensure the air vents are uncovered at all times. 
  2. Pour distilled vinegar solution down your drain line every few months to kill algae and fungi that might build up inside and block it.
  3. Inspect your drain pan now and then for cracks, misplacement, or overflowing, and act accordingly. That means replacing it or cleaning an overflowing drain pan with a wet-dry vac.

Final Thoughts

Air conditioner leaks are nothing pleasant. Remember, the leaks can destroy your house’s walls and ceilings and anything else around it.

Luckily, you know how to approach the problem once you notice air conditioner leakage. You also know what you must do to prevent leakage in advance. 

A regular HVAC tune-up goes a long way in preventing leaks. This kind of proactivity can save you leak patch-up costs down the road. Also, be aware that your AC blowing out water is different than when you have an AC leak.

About Roy Cohen

Roy Cohen has a burning passion for heating, cooling, and ventilation. He aims to help you save money on expensive repairs and bring you the best HVAC products. He has years of experience behind him in HVAC repair and garage maintenance.

You can find Roy at his LinkedIn or his email: [email protected]

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