Why did my AC stop and leak water?
A clogged condensate drain is one of the most common reasons an AC shuts itself off or drips water. Your AC pulls moisture out of the air as it cools. That water runs down a pan and out a drain line. When the line clogs with dust, slime or debris, the pan fills. Many systems have a float switch that cuts power to the AC before the pan overflows. So a dead AC with a full pan is often the switch doing its job. Climate Pros Tucson can match you with a licensed pro when clearing the line yourself isn’t safe or doesn’t work.
Why do monsoon weeks make it worse?
Dew points at Tucson’s airport sit in the 20s most of the year and jump into the high 50s in July and August. More moisture in the air means more water for your AC to wring out, so the drain carries more than usual. A line that was marginal in May can back up in the monsoon. Dust that blows in during storms ends up in the pan and the line, too.
Does it matter where the unit sits?
The fix depends on where your equipment lives.
| Rooftop package unit | Closet or garage air handler | |
|---|---|---|
| Where water goes | Drain line on the roof, often to a roof drain or scupper | Pipe to a floor drain, outside wall or condensate pump |
| Typical symptom | Stains on the ceiling below, water at the unit | Water on the closet floor, or a stopped AC |
| Float switch | In the unit’s pan | In the pan under the coil |
| Homeowner access | Roof, which is unsafe in summer heat | Often reachable indoors |
Package units are equipment a home may have, not a given. If yours is on the roof, leave the roof to a pro. About 68 days a year reach 100F or higher at the airport, and a flat roof in that heat is a fall and heat hazard.
What can you safely check?
- Turn the AC off at the thermostat, then at the breaker.
- Look for water in the pan or on the floor near an indoor unit.
- Find where the drain line ends outside. Clear obvious blockage at the end, such as insects or mud.
- A wet/dry vacuum on the drain end can pull out a clog from a closet unit.
- Dry the pan, restore power, and watch for a restart.
Don’t pour chemicals into the drain without asking a pro. Don’t bypass or tape the float switch. It is what protects your ceiling.
What needs a pro?
- The line is clear but the pan keeps filling, which can mean a bad slope or a cracked pan.
- A rooftop unit is leaking into the house.
- The coil is iced over. See AC freezing up, because ice melting can look like a drain problem.
- The condensate pump hums but does not move water.
Ask whether a tune-up includes clearing the line. See AC tune-up and AC repair. Related: AC not cooling checklist and monsoon humidity and your AC. Area overview: Tucson HVAC hub.
Water on the ceiling or an AC that won’t stay on
If water is reaching your ceiling or the AC will not stay on, you need a licensed pro on the roof or at the air handler. Call (520) 353-2520 and we’ll match you with a licensed local pro.