5 Common Causes of AC Water Leaks

High summer temps across the country are making us put our air conditioners in overdrive this year. Whether you have central air, a window unit, or a ductless mini split system, you might notice some moisture on or beneath your air conditioner. While a little bit of condensation is normal, puddles and steady drips are signs of appliance trouble.

If you suspect that you have an A/C unit leaking water, we’ll help you sort it out. Below are five of the most common causes of air conditioner leakages.

Signs Your AC is Leaking Water

Determining if you have a leaky AC unit is sometimes harder than you might think. Some leaks sneak up on you, starting small and worsening over time. The symptoms can fly under your radar. Here are some signs to watch for:

 

• Puddles and drips. If your air conditioner is leaking water or refrigerant, you may notice a pool or puddle gathering beneath the unit. Drips down the side of the unit are also possible. If the leak isn’t particularly severe, or if you use your air conditioner intermittently or infrequently, you may also see dried water stains where liquid has already evaporated.

 

• Inefficient cooling. A dip in cooling efficiency is one of the most common air conditioner problems, and this issue can be precipitated by an A/C leaking water or refrigerant. Even if there is no visible liquid on or around your unit, if you notice your air conditioner working harder to maintain the same temperature, or if you see an uptick in your energy bills that is otherwise unexplainable, a leak could be the culprit.

 

• Mildew. Mold and mildew thrive in moist environments, so a leaking air conditioner could facilitate their growth. Discoloration from mildew or that telltale musty odor could be the result of leakage.

 

• Corrosion. Properly maintained and functioning air conditioners should not develop rust. If you see signs of corrosion, inspect the unit for a leak.

 

• Depleted refrigerant. The cooling system in an air conditioning unit is closed, so you don’t have to top up the refrigerant periodically. If your refrigerant levels are low, that usually points to the substance leaking out somehow—a problem that should be immediately remedied. 

 

Common Causes of AC Water Leaks

Now you know what to look out for. But what causes an AC unit to leak in the first place? Here are five of the most probable cause:

1. The drain lines are clogged.

 An air conditioner is bound to generate condensation. We run the appliance in warm and humid weather, and when hot, moist air hits the comparatively cool unit, beads of condensation form. Properly installed and maintained air conditioners have mechanisms to safely manage this condensation. The water typically collects in a condensate drain pan and is then channeled through drain lines for removal from the system.

 Occasionally, the condensate drain line can become clogged by soot, grime, dust, or even algae. When this happens, condensate may back up, causing water to overflow from the drain pan. 

 If you’re comfortable with a little DIY AC maintenance, you can try clearing the drain line with a wet/dry vac. Another option is to break down some of the gunk with vinegar. Shut off the air conditioner and drain any accumulated water via the service valve. Pour equal parts water and white vinegar—about a cup of each—into the drain line. Wait an hour for the vinegar to do its job, then flush the system with water.   

2. The evaporator coils have frozen over.

 An air conditioner’s evaporator coils can freeze over for a few reasons. Often, the problem is simply that the coils are dirty with dirt, dust, or fine debris. It can also be caused by impeded air flow or inadequate refrigerant levels.

Frozen coils pose a couple of problems. They reduce the cooling efficiency of an air conditioner and cause an accumulation of ice. This ice later melts when the air conditioner is not in use, and the meltwater leaks from the unit.

If you have a leaky air conditioner, check the state of the evaporator coils. If they are coated in ice, shut down the system and allow the ice to thaw before cleaning up. If the coils are dirty, use a damp cloth to wipe them free of dust and grime. If the coils appear to be clean, check that nothing is impeding the air flow of the unit. Vents should be clear of obstructions and the air filter should be reasonably clean. Finally, you can check the refrigerant levels. If you do notice a low level of refrigerant, though, try to determine the cause. Low coolant levels could point to a secondary leak or poor installation.

3. The drain pan is corroded or damaged.

Another possible cause of air conditioner leakage is a damaged drain pan. If the unit is old, the pan may be corroded enough to allow water to escape. The pan will still collect the condensate, but some water will trickle through one or more tiny holes instead of channeling through the drain line. 

Check your drain pan for signs of damage. If it looks worse for wear, you can likely find an inexpensive replacement. Bear in mind, though, that if your drain pan is starting to fail, other parts of your air conditioning system may need to be replaced or serviced as well. 

4. The air conditioning unit was installed or serviced improperly.

Sometimes the appliance isn’t the problem—it’s the installation. If the drain pan or drain lines are misaligned, all or some of the condensate won’t be redirected away from the system. An inexperienced or hasty installer could also neglect to add the appropriate amount of refrigerant.

You might suspect a mistake in installation if you’re noticing issues shortly after a new system is set up or an existing system is serviced. Reach out to your technician to have the situation checked out. 

If your air conditioner had operated without a problem for many months or years before a leak arose, there’s probably something else at play.

5. The air filter needs to be replaced.

Regularly replacing the air filter is an essential task in taking good care of an air conditioning system. If the filter becomes clogged, airflow is obstructed, which can lead to inefficient cooling, frozen evaporator coils, and excess wear and tear. Over time, a leak can emerge as a secondary issue.

Fortunately, replacing an air conditioner’s filter could not be easier. Refer to the manufacturer’s instructions for guidance on which type of filter to use. You should be able to find a replacement at your local hardware or big-box home supply store.

 

The Importance of AC Maintenance

It’s easy to take our air conditioning systems for granted. The actual appliances are usually out of the way, so they might be easier to neglect than our kitchen and laundry appliances, for example.

But regular air conditioner maintenance is imperative. At first, neglect will result in inefficient cooling. Your unit will have run for longer to maintain a comfortable temperature. This will increase your energy bills, and you’ll spend more money out of pocket over time.

After many months or years of insufficient maintenance, the wear and tear of an overworked appliance compounds. A leak can develop or the machine’s cooling capacity can cease entirely. Ultimately, the air conditioner fails sooner than it otherwise would have, and you’re on the hook to pay for repairs or a full replacement. Fortunately, these problems can be avoided with a little forethought.

Preventive Measures to Avoid AC Water Leaks

A few simple maintenance tasks can help you to avoid the possibility of a leaky air conditioner. Here is some general guidance:

 

• Replace the air filter regularly. A key step in air conditioner maintenance is replacing the air filter. Typically, a new filter is recommended every 90 days, though defer to the guidance supplied by your air conditioner’s manufacturer. You may want to replace the filter more frequently depending on your climate, local air quality, and frequency of air conditioner use.

 

• Clean the evaporator coils and coil fins. A couple times per cooling season, use a damp cloth to wipe the evaporator coils and fins free of dust and debris. This will make them less likely to freeze over.

 

• Periodically check the condensate drain pan and drain lines. Once or twice per year, inspect your air conditioner’s drain pan and drain lines. If you see signs of corrosion or clogging, replace or clean parts as needed.

 

Why Do You Need a Home Warranty?

Of course, no matter how careful you are, problems can still arise. In those cases, a home warranty with HVAC coverage is especially beneficial. If your unit needs to be serviced, simply file a claim to have it checked out. If significant repairs or a replacement is necessary, you’re protected from the out-of-pocket costs.

 Liberty Home Guard offers a number of warranty plans with robust HVAC coverage. Learn more by calling (866)-983-0874.