AC Leaking Water in Lafayette

AC Leaking Water in Lafayette

An AC leak is a drainage problem, not a cooling one. The coil condenses water out of your air, it collects in a pan, and a line carries it outside. When you see water by the unit or a stain spreading on a ceiling, that path is blocked, cracked, or stuck. The system is generally still cooling while it leaks.

Lafayette's housing makes these calls particular. A lot of the homes are older custom builds on hillside lots, and the air handlers often sit in tight crawl spaces or low-clearance attics with cramped, awkward drain runs. Those tight installs clog and back up faster than a roomy garage unit, and on a hillside home the water tends to track down through framing and show up as a ceiling stain in a lower room before anyone sees a puddle.

Lafayette runs a touch cooler than the inland valleys, helped by the surrounding hills, but the AC still carries a real summer load, so a partly blocked drain will overflow under a long run. On the older systems we see here, condensate problems are routine and usually fixable with one part.

Common causes

Clogged condensate drain line. The most common cause, and Lafayette's tight crawl-space and low-attic installs make it worse because the drain runs are cramped and easy to block. Algae fills the line and the pan overflows. We clear it with a wet vacuum, flush it, and confirm flow before we leave.

Cracked or rusted drain pan. Many Lafayette systems are well past 20 years and the original pan has rusted at the seams or warped. Water drips straight through. We confirm the pan is the source, then replace it, and we're honest if the system's age means a replacement is the better use of your money.

Failed condensate pump. Hillside homes often can't gravity-drain the air handler, so a small pump pushes water out. When the pump or its float fails, the reservoir overflows. We test it and replace it when needed. It's an inexpensive part and a same-visit fix once we reach the unit.

Frozen evaporator coil that melted. A coil that ices from low refrigerant or weak airflow dumps a slug of water when it thaws, more than the pan holds. We check for frost on the coil and lines, then find what's behind it: a dirty filter, a tired blower, or a refrigerant leak. Drying the pan without fixing the freeze just buys you a day.

Tripped float switch from a hard-to-reach pan. Many of these crawl-space and attic units have a float safety switch that cuts the AC when the pan fills, which is what saves your ceiling. Because the units are awkward to reach, the underlying high water often goes unnoticed until the system quits. We clear the cause, test the switch, and confirm it resets.

How we diagnose it

• Locate the source despite the tight install: pan, line, pump, or a melting coil. Hillside units take scoping to reach.
• Inspect the coil for ice, which points to a refrigerant or airflow problem behind the water.
• Test the condensate pump and float safety switch.
• Clear and flush the cramped drain run, then confirm it drains fully under a pour test.
• Check the filter and blower airflow, a common root cause of coil freezing in low-clearance attic units.

$75 diagnostic, credited toward any repair over $200. You get a written quote before any work begins.

AC Leaking Water in Lafayette: common questions

Nearby and related

AC Leaking Water near Lafayette: Orinda · Moraga · Walnut Creek · Alamo .

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