Why is my AC leaking water inside the house?
An AC leaks water inside the house when condensate, the moisture pulled out of the air as it cools, can't drain the way it's supposed to. The usual culprits are a clogged condensate drain line, a cracked or overflowing drain pan, a dirty filter that lets the coil ice over and then thaw all at once, or a failed condensate pump. In Southwest Florida's humidity, the drain line is almost always where the trouble starts.
The Condensate Path, From Coil to Drain
Every central AC pulls double duty: it cools the air and, as a side effect, it also dries it. The cooling happens at the evaporator coil, the cold metal fins tucked inside the air handler. As warm, humid house air passes over that coil, moisture in the air condenses onto it, the same way a cold glass sweats on a humid afternoon. That water drips down into a shallow drain pan under the coil, then leaves through a small PVC pipe, the condensate line, that's supposed to carry it outside or to a floor drain. On an average Southwest Florida day, that quiet drip can add up to several gallons leaving the house without anyone noticing. A leak inside means water found a way around that path instead of following it.
A few points along that path tend to fail. The drain pan itself can crack or rust through after years of sitting wet. The line can come loose or get crushed. Systems with the air handler in a closet or attic, where the drain can't just run downhill to the outside, often use a small condensate pump to push the water out, and if that pump quits, water backs up fast. Many setups also include a secondary pan under the air handler with a float switch, a safety feature that shuts the whole system off if water rises where it shouldn't. So if the AC suddenly stopped running and there's water sitting in a pan nearby, that switch likely did its job. It isn't a separate mystery breakdown.
Why the Drain Line Clogs So Often Here
Southwest Florida's humidity means the coil is producing condensate nearly every day of the year, not just a few weeks in summer. Steady moisture sitting inside a warm, dark PVC pipe is exactly the kind of environment algae and mold-like sludge grow in. Given enough time, that buildup narrows the inside of the line until water can't move through it fast enough, backs up into the drain pan, and spills over the edge.
Homes with the air handler in the attic tend to see this sooner, since attics run hotter and speed up that growth. A brown ring or damp patch on the ceiling below the attic access is often the very first sign, well before the system ever stops cooling or shows any other symptom.
When It's Urgent, and When It Can Wait
Some leaks call for immediate action. If water is showing up where it should not be, shut the system off and call, and describe what you are seeing; judging how urgent it is happens to be our job. If the system also seems to be freezing up or struggling, do this first: Switch your thermostat to off (not just up) to protect the system if it's frozen or struggling. That stops the compressor, lets any ice melt on its own schedule, and keeps the leak from getting worse while someone takes a look.
If a burning smell ever shows up along with the water, shut the system off and call right away. That combination points to an electrical problem, not a simple clog, and it isn't something to wait out. Outside of those situations, an occasional damp spot near a floor vent or a slow drip that isn't spreading is usually fine to handle with a scheduled visit rather than an emergency one.
What to Check Before You Call
Start with the filter. A clogged filter starves the coil of airflow, and a coil that's not getting enough air across it can ice over. When that ice eventually melts, it often dumps more water than the pan and line were ever designed to handle at once, which is one of the most common self-inflicted causes of an indoor leak.
Next, look for a cleanout on the drain line itself, usually a capped vertical fitting near the air handler. Removing the cap and pouring a cup of plain water or vinegar through it, or running a wet/dry shop vacuum at the outdoor end of the line, can clear a mild clog. If that doesn't stop the leak, or it keeps coming back within a few weeks, the clog is probably deeper in the line than a homeowner can reach, or the pan itself has a problem. At that point, a professional AC repair visit can trace the whole line, clear what a vacuum can't reach, and check the pan and pump while the system is apart.
Stop a Condensate Leak Before It Reaches the Ceiling
Exclusive Cooling Solutions is a fully licensed, fully insured Cape Coral company, FL license CAC1823575, with a flat $150 service call and an upfront quote before any repair starts. Call or text (239) 350-5234, average response under 3 hours during business hours.