AC Leaking Water in Millbrae

AC Leaking Water in Millbrae

An air conditioner is designed to drip water, into a pan and out a drain line, not onto your floor. When water shows up around the indoor unit, the drainage path broke down. A clogged line is the most common reason, followed by an overflowing pan, a failed float switch, or a coil that iced over and melted. None of those is a dead system. Each is a part we can name and replace.

Millbrae has a climate worth knowing about. Summers here run mild for the Bay Area, with afternoons that rarely push hard against the cooling load. A system that was sized larger than the home needs will short-cycle in that kind of weather: it blasts on, satisfies the thermostat fast, and shuts off before it runs long enough to dry the coil. That short cycling, plus weak airflow from a dirty filter, is a common path to a frozen coil that later melts all over the closet floor. Hot inland cities push the opposite problem, a coil working flat-out in the heat.

Across the housing here, from the hillside customs to the older flatland ranches, the air handler usually lives in a closet or attic, draining the long way. The leak is usually a cheap fix. The reason to move fast is water damage, not heat. Our diagnostic is $99, credited toward the repair.

Common causes

Frozen coil from a short-cycling system. Common in mild Millbrae, where a system sized larger than the home needs short-cycles in the moderate weather. Short run cycles and low airflow let the coil ice up, then it melts and overruns the pan. We confirm the freeze, check airflow and refrigerant, and talk honestly about sizing if the system is chronically short-cycling.

Clogged condensate drain line. Algae and dust plug the PVC and the pan backs up and overflows. We vacuum the line at its outdoor end, blow it clear, flush it, and verify it drains fully. On long attic runs we also check the slope so it does not re-clog by next season.

Dirty filter restricting airflow. A clogged filter starves the coil of air and is a leading cause of freeze-ups, especially on systems running light cooling loads in a mild climate. We pull the filter, check the blower, and set you up so airflow stays adequate. Often this is the whole story behind the leak.

Failed float switch. The float switch should cut the system off when the pan fills. When it sticks closed, the unit keeps overflowing onto the floor. We test it, confirm it interrupts the cooling call, and replace it if needed. It is a small part that protects expensive flooring.

Overflowing or rusted drain pan. When the primary line clogs, the pan fills and eventually overflows or corrodes through. We inspect and clear the pan and replace it if it is rusted out, then trace upstream to the original blockage.

How we diagnose it

• Shut the system down and find the water source, then check whether the unit is short-cycling, which points to a sizing or airflow problem.
• Pull the filter and check blower airflow, the most common reason a coil freezes in a mild-climate home.
• Clear and flush the condensate line and confirm it drains all the way outside.
• Read refrigerant pressures and coil temperature with gauges if there is frost.
• Test the float switch so the system shuts off before the pan overflows again.

$99 diagnostic, credited toward the repair. You get a written quote before any work begins.

AC Leaking Water in Millbrae: common questions

Nearby and related

AC Leaking Water near Millbrae: Burlingame · Hillsborough · Menlo Park .

This is usually a ac repair in Millbrae job. See our ac repair overview or the Millbrae service area.