AC Leaking Water Through the Ceiling: Causes and Fixes
Attic air handlers drip a lot of water in a Texas summer. When the drain fails, it comes through the ceiling.
Need water help right now?
Call with the source and the rooms affected.
Call for emergency water extractionWhy is my AC leaking water through the ceiling?
An AC leaking water through the ceiling almost always has a drainage problem in the attic: a clogged condensate drain line, a full or cracked drain pan, a failed float switch, or a frozen coil that floods the pan when it melts. Turn the system off at the thermostat, catch the water, and keep people out from under a sagging ceiling.
Many homes in DeSoto and across North Texas have the air handler in the attic. In a long, humid summer it can pull many gallons of water out of the air each day, which drains through a small pipe. When that pipe clogs with algae and sludge, the water has nowhere to go but the ceiling.
Key points
- Turn the AC off at the thermostat to stop making water.
- A bulging ceiling is holding water; keep clear and catch the drips.
- Most leaks trace to a clogged condensate line or full drain pan.
- Wet ceiling drywall and insulation need drying or replacement.
Common causes
| Cause | Clues |
|---|---|
| Clogged condensate drain line | Primary pan full, slow or no drip at the outdoor drain outlet |
| Full secondary (emergency) pan | Water standing in the larger pan under the unit |
| Failed float switch | System kept running even though the pan was full |
| Cracked or rusted pan | Leak continues even after the line is cleared |
| Frozen evaporator coil | Ice on the coil or refrigerant line, weak airflow; often a dirty filter or low refrigerant |
| Disconnected drain fitting | Water running from a joint near the unit |
What to do right now
- Turn the system off at the thermostat. If the coil may be frozen, set the fan to on so it thaws.
- Put buckets and towels under the drip and move furniture and electronics away.
- Do not stand under a ceiling that is sagging or bulging. If water is near a light fixture, switch that circuit off at the breaker.
- If safe, check the attic pans and the float switch, and photograph them.
- Call an HVAC technician for the unit and an extraction crew for the wet ceiling, insulation and floor below.
Clearing the condensate line
Many homeowners can clear a simple clog. Find where the drain line exits outside, often near the outdoor unit or a wall, and use a wet vac on the end to pull the clog out. Some systems have a cleanout tee near the air handler where a cup of plain white vinegar can be poured to slow future algae growth. If water keeps backing up, the pan is cracked or the line is sagging, and a technician should look at it.
Drying the ceiling
Ceiling drywall soaked from above usually stains, sags or crumbles. Blown insulation above it compacts and holds water. A crew measures moisture in the drywall, framing and insulation, removes what cannot be saved and dries the rest with air movers and dehumidifiers. See ceiling leak water removal and AC leak water removal.
How to prevent the next one
- Change the air filter on schedule, usually every one to three months in summer.
- Have the condensate line flushed during spring AC service.
- Make sure the float switch works and the secondary pan has its own drain or switch.
- Add a water sensor alarm in the attic pan.
Written for homeowners and renters in DeSoto, TX and nearby cities. This guide is general information, not legal, insurance or engineering advice. See our editorial policy for how guides are researched and reviewed.
AC ceiling leak questions
Can I keep running the AC if it is leaking?
No. Running it keeps producing water that has nowhere to go. Turn it off at the thermostat until the drain is cleared and the pan is empty.
Should I poke a hole in a bulging ceiling?
Only if you are trained and it is safe. A bulging ceiling can give way suddenly. Keep people out from under it, catch drips and let a crew handle controlled drainage.
Why does my AC leak only in summer?
The unit removes the most moisture from the air in hot, humid months. That is when algae grows in the drain line and when a clog fills the pan fastest.
Is AC ceiling water dirty?
Condensate is fairly clean when it starts, but it picks up sludge from the pan and dust and insulation from the attic. Wet insulation is usually replaced.
More water damage guides
Category 1, 2 and 3 Water Explained
Clean, gray and black water, and why the category sets the cleanup.
Read the guide →How Long Does Structural Drying Take
Typical drying days by material and how crews know a room is dry.
Read the guide →Who Pays for Water Damage When You Rent
Landlord repairs, renters insurance and Texas tenant rights after a leak.
Read the guide →AC water coming through the ceiling?
Shut the system off and call for extraction and drying of the ceiling and rooms below.