air handler leaking water

Imagine this.

You’re off from work and plan to spend the day just relaxing in the cool and comfort of your home in West Mifflin, PA. After all, it’s one of those days that experts forecast will have an above-normal temperature this summer of 2024. So, you set the thermostat to a more comfortable level.

Unfortunately, your home remains warm and muggy even with the air conditioner running for over an hour. That prompted you to check your AC’s indoor unit, and that’s when you discovered your air handler leaking water.

So, where is that water coming from? And what should you do about it?

This guide discusses AC water leak causes and fixes, so read on.

Culprits Behind an Air Handler Leaking Water

Issues with the condensate drain line, evaporator coils, and refrigerant levels are among the primary causes of AC water leaks. These problems may result from aging-related wear and tear, improper installation, and a lack of HVAC maintenance.

Here’s a closer look at these culprits behind air handler leaks.

Problems With the Condensate Drain System

Your AC’s condensate drain system consists of a drain pan connected to a drain line. The pan collects condensation that drips from the evaporator coils, and the drain line channels the water out of your home.

So if the drain line or pan develops problems, the water may have nowhere to go. As a result, it may overflow, leading to your air handler leaking water.

Clogged Condensate Drain Line

Over time, dirt, dust, and debris can settle on your AC’s drain pan. If you have pets, their dander and fur can also find their way into your air handler and accumulate on the tray. As the pan collects water, these contaminants can clump up and clog the drain line.

Your air conditioner’s drain line can also become clogged with mold. Mold spores can quickly grow if they land on an item that remains wet for 24 to 48 hours. Since your drain pan is constantly damp while you use the AC, the chances of mold growing in it are high.

Overflowing Condensate Drain Pan

If the drain line clog becomes too severe, condensation that drips from the evaporator coils will begin to build up. The water will keep rising until it overflows unless you remove the clog.

Newer AC units have an overflow float switch that automatically turns the system off when it senses that the pan is about to overflow. However, the switch itself may become damaged and perform erratically. In that case, the AC will keep running and, as it does, continue producing condensation, causing the pan to overflow.

Many older AC units don’t have an overflow float switch. That means they’ll keep trying to cool your home (and produce more condensation) even if the pan is overflowing.

Leaking Drain Pan

Another possible culprit behind your air handler leaking water is a damaged drain pan that leaks water. Such problems are often due to old age, wear and tear, corrosion (for metal pans), or extreme temperatures that can cause pans to warp.

Regardless of the cause, a damaged drain pan will leak water, causing it to pool around your air handler.

Frozen Evaporator Coils

Your AC’s evaporator coils are cold metal pipes through which refrigerant passes. Together, they work to absorb heat and moisture from the air.

Over time, the evaporator coils can become coated with dirt, dust, debris, and other contaminants. This build-up interferes with condensation, potentially causing the water droplets to freeze.

As the problem progresses, more ice can form on the coils. The bigger the ice, the more water it can produce as it thaws.

All that water can then overtax the drain tray. Things may get bad enough to cause the pan to overflow and lead to your air handler leaking water.

Low Refrigerant Levels

As mentioned above, your AC’s evaporator coils work with refrigerant to absorb heat and moisture from the air.

Each air conditioner has a specific refrigerant level “requirement” to do its job right. If there’s not enough of this chemical, your AC won’t cool your home correctly, and the evaporator coils may freeze. From there, the thawing ice can result in an overflowing drain pan.

Low refrigerant levels may result from improper system charging during installation. For this reason, West Mifflin homeowners must choose a highly experienced, licensed HVAC contractor for new or replacement AC installations. These experts ensure each air conditioner they put in has the correct charge.

Leaking evaporator or condenser coils can also result in low refrigerant levels. These leaks may occur when an AC’s evaporator or condenser coils develop corrosion. Refrigerant leaks are expensive to fix and can have adverse health effects.

Next Steps

If you see water leaking from the air handler, please turn your AC off immediately. That will stop it from producing more condensation.

Next, wipe the area dry to prevent water damage and mold growth. If you have tools, you can perform the following basic air handler troubleshooting steps:

You should also check the interiors of the air handler for signs of ice. If you see any, please immediately contact a licensed HVAC company. They can conduct more thorough diagnostic tests and repair possible refrigerant leaks or coil issues.

Fix Your Leaking Air Handler ASAP

The primary culprits behind an air handler leaking water are problems with the AC drain system, frozen coils, and refrigerant leaks. If you experience this issue, please follow the steps and solutions discussed in this guide.

If you want the quickest resolution, the HVAC experts at South Hills Electric, Heating & Cooling, LLC can help. We’ve been serving West Mifflin, Pittsburgh, and the surrounding areas with high-quality, reliable HVAC and electrical services since 1993. So, you can count on our over 20 years of experience to help you address all your air conditioning woes.

Contact us today to schedule your air conditioner maintenance or service! We look forward to helping you ensure your AC is ready for summer.