Air Conditioner Unit Leaking: Causes and What to Do

Reviewed by Richard Morales, Co-Owner & FL Class B Air Conditioning Contractor (FL license CAC1819196)Updated Oct 15, 2026

Why is my AC unit leaking water?

Your AC pulls a lot of moisture out of Tampa’s humid air. That water is meant to run down a drain line and outside. When something blocks the path, it backs up and spills near the air handler, often in the attic, a closet or the garage.

The common causes are a clogged condensate drain line (algae and slime build up fast in our climate), a cracked or rusted drain pan, a dirty air filter that lets the coil freeze and then melt, a failed float switch, and low refrigerant that makes the coil ice over.

Safety note: Water near the air handler and electrical parts can be a shock hazard, so shut the system off at the thermostat and the breaker before touching anything wet.

Which part of the unit is leaking?

Is a leaking AC unit a refrigerant leak?

Sometimes. Refrigerant does not drip like water. It escapes as gas, and the clues are ice on the coil, weak cooling, a hissing sound or oily spots on the copper lines. Topping off refrigerant without finding the leak only buys a short break, so the leak has to be found.

Our FREE diagnosis includes a basic leak search with refrigerant leak detectors. If those cannot find the leak, we explain the next step in writing before anything is done. You approve a written quote before any repair begins.

Can I keep running the AC while it leaks?

It is best not to. A clogged drain can overflow into your ceiling, insulation or flooring, and a frozen coil can strain the compressor. Turn the system off until it is checked. A fan-only setting is fine for air movement if no water is coming out.

How do I keep it from happening again?

Change filters on schedule, keep the drain line clear and have the system tuned up each year. A tune-up includes a drain line flush and a refrigerant check, which catch small problems before they turn into water damage. The ENERGY STAR maintenance checklist covers the basics: ENERGY STAR maintenance checklist.

What does Home Therapist do?

We find where the water or refrigerant is coming from and fix it. Estimates and diagnosis are FREE on every visit, at any hour, and we are open 24/7. Same-day service is available on many jobs. See our AC repair in Tampa page, browse other common home problems, or call or text (813) 343-2212.

Frequently Asked Questions

Why is my AC unit leaking water inside the house?

The usual cause is a clogged condensate drain line or a cracked drain pan. A frozen coil from a dirty filter or low refrigerant can also melt and overflow. Shut the system off and have it checked before the water damages your ceiling.

Is it normal for the outdoor AC unit to drip?

Some water near the outdoor unit can be normal, especially from a heat pump or from the drain line outlet. Oily fluid, ice or a hissing sound is not normal and points to a refrigerant problem that needs a technician.

Can a dirty air filter make my AC leak?

Yes. A clogged filter cuts airflow, so the coil gets too cold and freezes. When the ice melts, more water hits the pan than the drain can handle, and it spills. Replacing the filter often solves a mild case.

Should I turn off my AC if it is leaking?

Yes. Turn it off at the thermostat, and at the breaker if water is near electrical parts. Running it keeps making condensate and can damage the compressor if the coil is frozen. Then call us for a FREE diagnosis.

Do you charge to diagnose a leaking AC?

No. Diagnosis and estimates are FREE on every visit, at any hour, with no service call or after-hours fee. Many Tampa companies charge just to diagnose. You approve a written quote before any repair begins.