AC Leaking Water in Danville

AC Leaking Water in Danville

An AC that leaks water is doing its job. The cold evaporator coil pulls moisture out of your air, that water drips into a pan, and the pan drains through a small line to the outside. When you see water on the floor, the ceiling, or running down the air handler, one part of that drainage path has failed. The cooling itself is usually fine.

In Danville this shows up two ways depending on how the system was installed. Homes that run the air handler in an attic give you a brown stain on a bedroom or hallway ceiling before anyone notices a puddle. Older ranches with the unit in a closet or tight crawl space let the water sit low, so you find it by stepping in it. Either way the cause list is short.

Heavy summer AC load is what triggers it here. Danville hits the 90s through the summer, the system runs for hours, and a drain line that is half blocked with algae finally backs up under that volume. It is one fixable part most of the time, not a sign the whole system is done.

Common causes

Clogged condensate drain line. The most common one by a wide margin. Algae and slime build up inside the drain line over years of running. The pan fills faster than it drains and overflows. We clear the line with a wet vacuum at the termination and flush it, then confirm flow. On attic units we check the secondary drain too.

Cracked or rusted-through drain pan. Older systems past 20 years often have a metal primary pan that has rusted at the seams, or a plastic pan that warped. Water drips straight through onto the platform or ceiling. We confirm the leak is the pan and not the line, then replace the pan. On end-of-life systems we tell you so at the estimate rather than patching.

Failed condensate pump. Closet and crawl-space units that can't gravity-drain use a small electric pump to push water up and out. When the pump motor or float fails, the reservoir overflows. We test the pump's switch and motor, and most of the time it is a straight pump replacement, an inexpensive part and a same-visit fix.

Frozen evaporator coil that melted. If the coil iced over from low refrigerant or restricted airflow, it dumps a large slug of water all at once when the system cycles off and the ice melts, more than the pan can hold. We look for ice or frost on the coil and lines, then chase the root cause behind it: a dirty filter, a failed blower, or a refrigerant leak. Clearing the water without finding that leaves the real problem running.

Tripped or stuck float switch. Many Danville attic installs have a safety float switch that shuts the system off when the pan fills, which is what protects your ceiling. If it nuisance-trips or the wiring corrodes, the AC quits and you find water that already overflowed. We test the switch, clear the cause of the high water, and verify it resets cleanly.

How we diagnose it

• Locate the actual source: pan, primary line, secondary line, or pump. We trace where the water originates before touching anything.
• Inspect the evaporator coil for ice or frost, which points to a refrigerant or airflow problem behind the leak.
• Test the condensate pump and the float safety switch for proper operation.
• Clear and flush the drain line, then pour water through the pan to confirm it drains fully.
• Check the air filter and blower, since restricted airflow is a frequent root cause of coil freezing in attic systems.

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

AC Leaking Water in Danville: common questions

Nearby and related

AC Leaking Water near Danville: San Ramon · Alamo · Blackhawk · Walnut Creek · Pleasanton .

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