Why Is Your AC Leaking Water? 6 Potential Causes

May 18, 2022
Leaking AC in Seattle, WA

Air conditioning units are relatively complex, and for them to effectively cool down your Seattle, WA household, it requires many different components working together harmoniously. With so many parts collaborating to keep the appliance running, there are a variety of things that can potentially go wrong with the equipment. When an AC unit does malfunction, you may notice several different symptoms, but one of the most common occurrences is the appliance leaking water. Not only is a leaking AC unit a clear red flag that something’s wrong with the system, but it can also cause major water damage in your home.

A leaking air conditioner can be caused by multiple different underlying issues. In most cases, you’ll need to have your local cooling professionals fix whatever’s causing the leak to restore the appliance to healthy operation. However, there are certain instances when you may be able to troubleshoot the frustrating problem yourself.

1. Frozen Evaporator Coils

The evaporator coils are a crucial part of your indoor air conditioning unit, and they have the major job of absorbing heat from inside your household. However, if a refrigerant leak occurs or something interrupts the cooling system’s airflow, it can result in the coils becoming frozen. Then, they will inevitably thaw out, and that will create quite a bit of extra moisture within your AC unit. Most likely, it will be more liquid than the appliance is equipped to drain effectively, which means that some of it will spill out into your home.

There are a variety of possible causes for your AC unit’s evaporator coils becoming frozen. In many cases, it’s the result of an airflow blockage, which could be due to an issue with your air filters, vents, ducts, or other components of your household HVAC system. It could also be that your cooling system is low on refrigerant. Either way, it’s probable that you’ll need HVAC professionals to diagnose and remedy the issue for you to prevent further leakage.

2. Clogged Condensate Drain Line

Part of your air conditioner’s job is to dehumidify the air in your home, which involves pulling moisture from the oxygen. That water then moves through the unit’s condensate drain line, through your home’s plumbing system, and out of your household. However, because that moisture often contains particles of dirt, dust, and other pollutants, the line can occasionally get clogged up, preventing further liquid from draining properly. Then, as the air conditioner continues to dehumidify your indoor air, the moisture won’t have anywhere to go, and it will eventually overflow the appliance.

If you know what you’re doing, you may be able to clean out your air conditioner’s condensate drain line by scrubbing it with a long wire brush. If you’re able to successfully remove all of the gunk, that should put an end to your water leak issue. However, if you don’t have the right tool or you’re dealing with a severe clog, you’ll want to let the expert technicians at Brennan Heating & Air Conditioning handle it.

3. Disconnected Condensate Drain Line

If your home’s cooling system has been recently installed, repaired, or tuned up and is suddenly leaking water, it could be the result of the condensate drain line being loose or disconnected. Sometimes, if a contractor is careless or makes a mistake, they may inadvertently knock the line loose. In rare cases, the drain line may become disconnected on its own after several years of use. When this happens, it will frequently result in water pooling on your floor or leaking through the ceiling, depending on the location of your AC unit.

If your cooling system’s condensate drain line has become disconnected, you’ll need to have cooling professionals fix it for you. You can also reduce the risk of this happening in the future by only working with skilled, reputable HVAC technicians, like our friendly team at Brennan Heating & Air Conditioning.

4. Broken Condensate Pump or Float Switch

If your household HVAC unit is installed in the basement or attic, it may be more difficult for it to move water through its drain line and out of your home. In those cases, the use of a condensate pump is required to remove the built-up moisture from the system. Typically, the unit will also feature a reservoir with a float switch. When the reservoir fills up enough to activate the float switch, the pump will turn on and push the water through the drain line. Or at least, that’s how the process works when everything is operating properly.

Sometimes, either the condensate pump or float switch can break or malfunction. When that happens, the moisture won’t have any means of draining from the system, and it will just continue to accumulate until it starts to overflow the reservoir. Then, it will start spilling out into your home. If your AC unit’s condensate pump isn’t working, you’ll need to have the pump or float switch professionally repaired to put a stop to the leaking.

5. Damaged Drain Pan

Your air conditioner’s drain pan is located either underneath the evaporator coils or in the air handler, and its primary function is to catch the moisture from condensation as it drips and accumulates. Then, before enough liquid can accumulate to fill the pan, the water will flow into the condensation drain line and out of your home. However, if that drain pan becomes significantly corroded or damaged, it won’t be able to reliably catch and hold the moisture. Instead, the water will end up spilling out of the appliance and into your home.

Corroded or rusted drain pans are especially common in air conditioners that are more than 15 years old. In those cases, it will usually be necessary to have the pan replaced. Alternatively, if the pan is cracked, it may be possible to repair it effectively and continue using it. If you’re careful, you might even be able to patch it up yourself using a water-resistant sealant. Alternatively, our team at Brennan Heating & Air Conditioning can either repair or replace it for you to restore the system to a healthy, leak-free operation.

6. Excessive Condensation Build-Up

In some cases, your air conditioner may simply be experiencing too much condensation for the drainage system to handle, even if everything’s working properly. When this happens, it’s inevitable that some amount of that extra moisture is going to drip or spill out into your home’s interior. There are several potential causes for excessive condensation, and each one has its own ideal solutions.

  • Clogged ducts, vents, or air filters hampering airflow
  • Extreme household humidity
  • Poor home ventilation
  • Poorly insulated air ducts

Replacing your air filters, cleaning your vents, and scheduling a duct cleaning appointment are always prudent measures if your AC unit is leaking, but there’s no guarantee that any of those tasks will solve the problem. If you’re not sure what’s causing all the extra condensation, your best bet is to let your trusted HVAC technicians inspect your home and setup. They should be able to find the root of the issue and determine the best solution.

Reliable Heating and Cooling Professionals

If your Seattle area household is experiencing air conditioning problems, we at Brennan Heating & Air Conditioning are always available to help. Additionally, our skilled team can handle any issues you may have relating to heating, water heaters, air duct cleaning, and electrical systems. We offer 24/7 heating and cooling repairs, financing options on approved credit, and free energy consultations. Give us a call today if you’d like to schedule an appointment!

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