AC Troubleshooting
Why Is My AC Leaking Water? What South Florida Homeowners Should Do
Published October 24, 2026 · By the BrisaTide team
Finding water under your air handler or dripping from a ceiling is alarming — and in South Florida, extremely common. Your air conditioner does not use water to cool, but it produces plenty: every hour it runs, it pulls humidity out of Miami air, and that moisture has to drain somewhere.
When the drainage path works, you never think about it. When it clogs or overflows, the water goes wherever gravity takes it — often into ceilings, walls, and flooring. Most AC leaks have a short list of causes, and acting quickly keeps a small problem from becoming water damage.
Where the Water Normally Goes
As warm, humid air passes over the cold evaporator coil, moisture condenses on it — the way water beads on a cold glass. That water drips into a drain pan under the coil and flows out through a PVC condensate drain line.
A South Florida system can produce several gallons of condensate on a humid day. A small pipe doing a big job is why even a partial clog shows up quickly here.
Cause 1: A Clogged Condensate Drain Line
This is the number one cause of AC water leaks in Florida, and it is not close. The inside of a condensate line is dark, warm, and constantly wet — perfect conditions for algae and mold. Over months, that growth narrows the pipe until the line blocks completely.
When it clogs, water backs up into the drain pan. Then either a float switch shuts the system down to protect your home, or — if there is no working switch — the pan overflows. If your AC stopped cooling and there is water in the pan, a clogged drain is the first suspect.
Cause 2: The Float Switch Did Its Job — or Did Not
A float switch is a small, inexpensive safety device in the drain pan or line. When water rises too high, the float lifts and cuts power — trading a no-cool afternoon for a dry ceiling. If your system shut off and you find standing water near the indoor unit, the switch may have just saved you from real damage.
The risk runs the other way, too. Older systems may have no float switch, and switches can stick or fail. Ceiling stains, bubbling paint, or a musty smell near the air handler closet — without the system ever shutting off — suggest the protection is missing or dead. Ask a technician to check it, and add one if needed; it is among the cheapest protections in the system.
Cause 3: A Frozen Coil That Thawed
When an evaporator coil freezes — usually from a clogged filter restricting airflow, or low refrigerant — ice builds on the coil and in the pan. When it melts, it can release more water than the pan and drain line can handle at once, and the excess spills over.
If the leak comes and goes, or you saw ice on the refrigerant lines before the water appeared, a freeze-and-thaw cycle is a likely explanation. Turn the system off, let it thaw fully, replace the filter, and open all vents. If the coil freezes again, stop: repeat freezing needs a technician to find the underlying cause.
Cause 4: A Rusted or Cracked Drain Pan
Drain pans live a hard life — constantly wet, in warm attics and closets, for years. Metal pans on older systems can rust through; plastic pans can crack with age. When the pan itself fails, water drips straight through even though the drain line is perfectly clear.
A pan leak tends to be a slow, steady drip directly under the air handler rather than a sudden overflow, sometimes with rust stains marking the path. Replacing a pan is a professional job — it usually sits under the coil — but catching it early keeps the repair to the pan instead of the pan plus the ceiling below.
Safe Steps to Take Right Now
While you arrange help, a few steps limit the damage, and none require opening the unit. Move anything stored near the air handler out of the wet area, put towels down to catch drips, and take a photo — it helps a provider understand the problem before they arrive.
- ▸If water is overflowing or near electrical components, turn the system off at the thermostat
- ▸Replace the filter if it is clogged — restricted airflow contributes to freezing and excess condensate
- ▸Check the outdoor end of the drain line is not buried, kinked, or blocked by mulch or landscaping
- ▸Do not pour bleach or chemicals into the drain line unless the manufacturer recommends it — the wrong product can damage the coil and pan
- ▸Do not keep resetting a system a float switch shut down; the water that tripped it is still there
Why Speed Matters — and Getting It Fixed
Water inside a warm Florida home does not stay a small problem. Warmth and humidity are exactly what mold needs, and growth can start on wet drywall within a day or two, turning an AC repair into drywall, paint, and flooring work. If a ceiling is bulging with water, keep people out from under it — that is a safety issue.
A provider's visit for a leak usually covers clearing the drain line, checking the float switch and pan, and confirming the coil is not freezing. BrisaTide connects South Florida homeowners with independent local HVAC providers. Request a local pro through our AC repair page or call 786-741-7667, and mention where the water is showing up — that detail helps match your request. Providers are independent businesses; you hire the one you choose, directly.
Rather have a pro look at it?
If the checks above point past the safe DIY line, request a local pro for AC Repair — or call 786-741-7667. One request, independent local providers, you choose who to hire.