Condensate Leak in the Attic in Pleasant Hill, CA

Condensate Leak in the Attic in Pleasant Hill

Pleasant Hill sits inland in the Diablo Valley, so its summers get hot and the AC carries a heavy load. A lot of the older ranch homes here have the air handler tucked into a shallow attic above finished living space. When that unit runs hard through a heat wave, it makes a steady stream of condensate, and if the drain can't carry it, the water comes through the ceiling below.

This is almost always one fixable part, not a dead system. The cooling coil pulls humidity out of the air, that water drips into a pan, and a drain line carries it outside. Block the line, lose the pump, crack the pan, or have a float switch that never trips, and the water rises until the emergency pan and float catch it, assuming those were installed and still work. On a lot of these older Pleasant Hill attic systems, the secondary protection is the part that was skipped.

Because the summer cooling load here is real, these attic units run for hours at a stretch, so a partly clogged line that might limp along in a cooler town overflows fast in Pleasant Hill. We see it most on the first hot week of the season, when a drain that quietly silted up over the winter gets hit with full runtime. We find the actual blockage and rebuild the drain so it can be serviced, instead of just flushing it.

Common causes

Clogged primary condensate line. The most common cause. Algae and biofilm plug the drain at the trap or an elbow, and water backs up into the pan and over onto the ceiling. We clear the line from the termination, confirm it flows, treat it, and add a cleanout if the original run had none so it's serviceable next time.

Float switch missing or failed. The safety float is supposed to shut the AC off before the pan overflows. In these older flatland ranches it was often never installed, or it corroded and stuck. We lift-test it for shutdown and install a proper float switch on the pan and secondary drain when it's missing.

Failed condensate pump. Where the shallow attic unit can't gravity-drain, a pump lifts the water out. A burned-out motor or a stuck check valve lets water collect until it spills. We test the pump under load, replace it when it isn't lifting, and confirm it has a safety switch wired to cut the AC on a backup.

Cracked or rusted primary pan. Steel pans on these decades-old systems rust through, and plastic pans crack. A leaking pan ruins the ceiling even with a clear drain. We inspect with a light and mirror, replace the pan when it's gone, and give you the honest call on whether the pan or the whole aging air handler is worth fixing.

Tight-attic install out of level. Pleasant Hill's shallow attics make for cramped installs, and units often sit off level. The pan then holds water at the low corner and overflows there even when the drain is clear. We level the unit, shim or re-set the platform, and confirm the pan slopes to the drain.

How we diagnose it

Confirm the water is condensate from the attic air handler, not a roof leak finding the same ceiling bay.
Inspect the primary pan, emergency pan, and drain lines for standing water, rust, cracks, and a working trap.
Lift-test the float switch and verify the system shuts off; flag it if there's no switch at all.
Clear and flow-test the primary line under full runtime, and test the pump and its safety switch where the unit can't gravity drain.
Level the unit in the attic and verify pan slope before we call it done.

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

Condensate Leak in the Attic in Pleasant Hill: common questions

Do you cover Pleasant Hill and the rest of the Diablo Valley?

Yes. We're based in San Ramon and cover Pleasant Hill, Walnut Creek, Concord, Lafayette, and Martinez. A ceiling stain during a heat wave is a same-day priority for us when the schedule allows, because the damage grows every hour the system keeps running and overflowing. Call (925) 999-4095.

Why does this happen right when the first heat wave hits Pleasant Hill?

Because that's when the system suddenly runs for hours at a time. Over a cool winter and spring the drain line can silt up or grow algae while the AC sits idle. The first hot week of summer hits the unit with full runtime, it makes condensate faster than a marginal drain can handle, and the pan overflows. Clearing and treating the line before summer is the cheap way to avoid the ceiling repair.

It leaked once and stopped. Is the problem gone?

No. Condensate only forms while the AC is running, so the leak stops the moment the system cycles off or the weather cools. The clog or failing pump is still there and will overflow again on the next hot stretch. We run the system and watch the pan fill and drain in real time to confirm the path is actually clear, not merely dry between cycles.

Nearby and related

Condensate Leak in the Attic near Pleasant Hill: Walnut Creek · Concord · Lafayette · Martinez .

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