AC Leaking Water Inside: What to Check First

An AC leaking water inside the house is nearly always condensate, the water the system pulls out of the air, overflowing because it cannot drain away. The fix is often simple, but the water can do real damage to a ceiling, a closet floor or the drywall around the air handler if it runs for long. Turn the cooling off now, then work through the checks below. If they do not stop it, One Call Home Pros connects you with a vetted, licensed, insured local HVAC professional.

The short answer

As your system cools, moisture from the air condenses on the indoor coil and drips into a pan underneath. A drain line carries that water outside or into a household drain. In a humid climate, that is a lot of water every day.

When the drain line clogs with algae, sludge or debris, the pan fills and overflows. A cracked pan, a disconnected drain line or a frozen coil that is now thawing can do the same. The water ends up on the closet floor, in the ceiling below an attic unit, or running down a wall.

What to do first

These steps stop the water and protect the house. They are all safe, and they are the right start for any AC leaking water indoors.

1. Turn the system to off at the thermostat. Cooling makes more condensate, so stopping it stops the water.
2. Put towels down and set a bucket under any drip. If water is coming through a ceiling, move furniture and electronics out from under it.
3. If water has reached an outlet, a light fitting or anything plugged in, switch off that circuit at the breaker.
4. Take photos of the leak, the ceiling and the area around the indoor unit.
5. Check the air filter. A blocked filter can freeze the coil, and the melt overflows the pan when the system stops.

What to check next

With the cooling off, you can look without opening anything.

• The drain pan. If you can see it, check whether it is full of water. A full pan means the drain line is blocked.
• The float switch. Many systems have a small safety switch in the pan or on the drain line. If it has tripped, the system may refuse to cool until the water clears.
• The outside end of the drain line. Find the small pipe where condensate leaves the house, usually near the outdoor unit or a foundation wall. When the system runs normally, it drips steadily. If it is dry while the inside leaks, the line is blocked.
• The secondary pan. Attic air handlers often sit in a second pan with its own drain. Water in that pan means the main drain has already failed.

When to stop and call a pro

Leave the air handler’s panels closed. Behind them are the blower, the coil and electrical parts, and some units have a heat strip that carries high voltage. Do not cut into the drain line, and do not pour bleach or chemical drain cleaner into it. Some cleaners damage the pan and the line, and bleach can corrode parts.

Call a pro if water keeps appearing after the system is off, if the ceiling is sagging or stained, if there is ice on the coil or the copper lines, or if the leak came back soon after a cleared drain. If you want to clear the line yourself in future, ask the pro whether your system has a cleanout point and what is safe to use in it.

Why it is so common in a Florida summer

South Florida’s humidity means an air conditioner removes far more water from the air than a system in a dry climate. That water is warm and slow-moving in the line, which suits algae. Over a long cooling season, a slimy plug forms and narrows the pipe until it stops.

Where the indoor unit sits decides what gets damaged first. In a hall closet, it is the closet floor, the baseboards and the carpet next door. In a garage, it is usually only the concrete. In an attic, it is the ceiling drywall and the insulation above it, and a wet ceiling can sag and fail. Water that sits in drywall or under flooring also feeds mould, which is why a slow leak deserves as much attention as a fast one.

What the pro looks at

An HVAC professional called for an AC leaking water will usually:

• Clear the condensate line and confirm water flows freely to the outside
• Check the pan for cracks and rust, and the secondary pan if there is one
• Test the float switch so it shuts the system down before the next overflow
• Check the filter, the coil and the refrigerant charge if the coil was frozen
• Check that the drain line has a proper slope and has not come apart at a joint

If the leak came from a frozen coil, clearing the drain alone will not solve it. The pro looks for the airflow or refrigerant problem behind the ice.

How One Call fits in

One Call Home Pros is a connector, not an HVAC company. Tell us where the indoor unit is, where the water is showing up and whether the system was cooling normally before the leak. We match you with a vetted professional who holds the Florida licence for air conditioning work and carries insurance. The pro finds the cause and puts it right. One Call vets the pro, arranges the visit and stays with you until the job is finished.

You pay One Call, and One Call pays the pro, so ask what the price covers before the work begins. For more, see AC repair, or the pages for AC repair in Fort Lauderdale, Margate and Coconut Creek.

Get the leak stopped

Turn the cooling off and protect the floor. Then tell One Call where the water is coming from, and we connect you with a vetted, licensed local HVAC pro.