Condensate Leak in the Attic in Lafayette

Condensate Leak in the Attic in Lafayette

Cooling a house produces water. The evaporator coil condenses moisture out of the air, it drips into a pan, and a drain line carries it away. When that line clogs, the pan overflows, and in an attic install the only place the water goes is down through the ceiling. The first symptom in most Lafayette homes is a stain, sometimes a sagging patch of drywall, not a sound.

A lot of the older hillside customs up here were built with tight crawl spaces and low attic clearance, which is exactly the kind of install where the condensate routing was a compromise from day one. A drain run that barely slopes, a pan that's hard to reach, an air handler shoehorned under a low roofline: each of those makes a clog more likely and harder to spot early. The good news is that this is almost always one part, not a dead system. Usually a plugged line, a stuck float switch, a cracked pan, or a worn-out condensate pump.

Because access here is genuinely tight, the worst outcome is a leak that runs for weeks behind drywall before it's found. The emergency pan and the float switch under the air handler are the last line of defense, and on a lot of these older Lafayette installs one or both were never set up right.

Common causes

Clogged primary condensate line. Biological slime builds inside the drain over a cooling season and blocks it, so the pan backs up and overflows. We clear it with a wet vacuum from the termination and flush the line clean, then pour water through to confirm it drains. In these tight attics we make sure there's a usable cleanout so the next service isn't a wrestling match.

Float switch that didn't cut the system. A safety float is supposed to shut the AC off when water rises in the pan or drain. On older Lafayette installs it's often missing entirely or wired in a way that never worked. We test it by raising the float and watching the system shut down, and we add one where an attic unit has no protection.

Improper pan slope in a tight attic. When an air handler is wedged under a low roofline, installers don't always get it sitting level toward the drain. Water then pools in a corner and spills over instead of draining. We check the pan's pitch and shim the unit so it actually runs to the fitting.

Failed condensate pump. Hillside attic units below their drain exit rely on a small pump to lift the water out. When the motor or its float fails, the reservoir overflows. We power-test the pump, check the check-valve, and replace it if it won't clear its tank reliably.

Cracked or corroded primary pan. An aging pan on an older install can crack or rust through and leak straight to the ceiling even with a clear drain. We inspect it with a light and mirror, confirm it holds water, and replace any pan that doesn't.

How we diagnose it

• Get eyes on the air handler in the low attic and find where the water is actually escaping.
• Pour water through the primary pan to tell a clog apart from a cracked or mis-sloped pan.
• Lift the float switch and confirm the system shuts off the way it's supposed to.
• Check the drain line slope through the framing and clear any blockage from the termination.
• Inspect the secondary pan for standing water, the sign the primary already failed.

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

Condensate Leak in the Attic in Lafayette: common questions

Nearby and related

Condensate Leak in the Attic 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.