Your air conditioner should cool your home, not leave a puddle under the unit. If you’ve spotted moisture around your system or noticed a steady drip, it’s probably more than condensation. Ignoring it won’t make it go away. Rosenberg Plumbing & Air in San Antonio, TX, helps homeowners figure out what’s wrong and what needs fixing before a leak causes water damage. Let’s explore the most common reasons for a leaky AC and what to look out for.
Why Your AC Has Water in the First Place
Your air conditioner isn’t supposed to leak, but it typically produces some water. That’s part of how cooling works. When warm air moves across the cold evaporator coil, moisture from the air condenses on the coil’s surface. This water needs to go somewhere, so your system includes a drainage setup. The coil drips condensation into a small pan, which drains through a pipe that leads outside or into a designated drain line.
This process is constant during hot, humid days. The more moisture the air holds, the more water is in the system. When everything works right, you won’t notice it. The water leaves the house quietly, and your AC keeps running smoothly. However, the water may remain in the house if something gets blocked, breaks, or shifts out of place. That’s when it starts dripping in places it shouldn’t.
Clogged Drains Are a Common Culprit
If your air conditioner leaks water inside the house, a clogged drain line could be the reason. This small pipe removes moisture from the condensate pan and carries it away. But because it deals with warm, damp air, it’s also a perfect place for sludge and algae to grow. Over time, dust and organic material collect in the pan, and some of it flows into the drain line. If enough builds up, the line clogs.
Once that happens, the water has nowhere to go. It backs up into the drain pan and spills over the edge. That might show up as a slow drip around the base of the indoor unit, or it might look like a small puddle forming near the air handler. If the unit is in a closet or attic, you might not see it at first. But the signs will follow. You could notice musty smells, water spots on the ceiling, or damp flooring nearby.
Clearing a clogged drain line takes more effort than simply pouring something down the pipe. The buildup inside often requires suction, pressure, or a technician’s tools to clear it without damaging the line. If you’ve had more than one leak in the same area, this part of the system is a smart place to start looking.
Drain Pans Won’t Last Forever
Your AC’s drain pan might seem like a minor component, but it plays a big role in managing condensation. It sits just below the evaporator coil and catches the moisture that drips off the coil during cooling. That pan then channels the water into the drain line. If the pan cracks, rusts, or slips out of position, water can leak before it reaches the pipe.
Most drain pans are made of metal or plastic. Metal ones can corrode, especially in older systems, and plastic ones can warp under heat or pressure. Once a crack forms, the water doesn’t pool; it flows out immediately. Depending on the extent of the damage, it might appear as a slow drip or a fast leak.
When a Frozen Coil Is Hiding a Bigger Issue
One of the less obvious causes of water leaks is a frozen evaporator coil. This problem starts quietly but usually ends in a mess. When the coil freezes, it normally stops draining condensation. Instead, the water freezes along with the coil. Once the system turns off and the ice melts, it releases more water than the pan can handle. That sudden melt can overflow the drain pan, creating puddles around the air handler.
Coils don’t freeze without a reason. A common cause is restricted airflow. If your filter is clogged or your ducts are blocked, the coil won’t get enough warm air to stay above freezing. Another cause is low refrigerant, which can cause the coil to drop below its normal operating temperature. Either way, a frozen coil isn’t just a water issue. It signals a larger system imbalance that needs immediate attention.
You might first notice a drop in cooling power. Rooms may feel warmer even though the AC runs constantly. Then you hear water dripping or see ice buildup inside the unit. If that’s happening, it’s time to shut off the system and call a professional. Running a frozen coil can lead to permanent damage, including compressor failure.
Leaks Can Spread Damage You Can’t See
A leaking air conditioner doesn’t just make a mess. It affects parts of your home that aren’t easy to fix. Even a small drip can soak insulation, stain drywall, or warp floorboards if the indoor unit sits above a ceiling or inside a wall cavity. If the leak persists without notice, it can lead to mildew or bacterial growth behind the walls.
That trapped moisture doesn’t dry out easily. Once it’s there, it keeps the area damp, allowing mold to take hold. That can impact air quality and make your home smell musty, especially when the system cycles on. People with allergies or asthma may feel worse indoors because the air picks up those mold particles and spreads them through the ductwork.
It doesn’t take a major flood to cause this kind of damage. Even a small leak that lasts a few days can create long-term problems. Fixing the source quickly keeps it from spreading and saves you from having to repair more than just the AC.
Your Air Quality Takes a Hit When Water Builds Up
Excess moisture inside your system doesn’t just damage materials; it affects the air you breathe. When water collects inside the unit or ductwork, bacteria and mold find places to grow. That growth doesn’t always stay in one spot. Spores can spread through the air each time the fan runs. You may notice an odd smell at first, especially one that is sour or damp. But even without a smell, indoor air can carry those particles into every room.
Catching leaks early helps prevent that bacteria from building up in the first place. Once it starts, it takes more than just a filter change to clean it out. In some cases, parts of the system have to be disinfected or replaced.
Maintenance Keeps You Ahead of the Leak
Most AC leaks don’t start with a big failure. They usually build slowly, starting with something small like dust buildup, a slightly misaligned part, or a minor blockage. Regular maintenance gives the technician the opportunity to catch issues before they become visible leaks.
Stop Your AC From Leaking
Even small AC leaks can lead to mold, ceiling stains, or a system breakdown if you wait too long. The sooner you notice a problem and take action, the easier it is to fix. If your air conditioner is leaking or just acting strange, let Rosenberg Plumbing & Air take a look before it turns into a bigger AC repair bill. We also offer AC maintenance, duct cleaning, and indoor air quality solutions. Contact Rosenberg Plumbing & Air today!
Tags: AC Repair, HVAC Tips