AC Leaking Water in Alamo, CA | Bay Area HVAC Service

AC Leaking Water in Alamo

Most Alamo cooling calls about water come from the same place: a condensate drain that stopped draining. Your evaporator coil pulls moisture out of the air while it cools, and that water collects in a pan under the coil. A PVC line is supposed to carry it out of the house. When the line clogs with algae or sediment, the pan fills and the water finds the next lowest path. In a lot of Alamo homes that path is a finished ceiling below an attic-mounted air handler.

It shows up here partly because of how the homes are built. Plenty of Alamo properties are large enough to run a second system for an upstairs zone or a guest wing, and when that second air handler is tucked in the attic it usually drains through a long, gently sloped line. Long runs clog more easily and overflow with less warning. The fix is almost always one part or one cleaning, not the equipment itself.

Heavy summer cooling makes it worse. Alamo gets real heat, the coil runs for hours, and it produces a steady stream of condensate. A drain that barely keeps up in spring tends to back up once the system is running flat out in July.

Common causes

Clogged condensate drain line. The most common cause by far. Algae and slime build up inside the PVC line and the pan backs up. We clear it with a wet vac on the termination outside, flush the line, and confirm flow end to end. On attic units we add a few minutes to check the secondary drain and the slope of the run.

Overflowing or rusted-through drain pan. Older Alamo systems sometimes have a steel primary pan that has rusted at a seam, or a secondary emergency pan full of standing water because the float never tripped. We inspect both pans, and if the primary is corroded we put a pan replacement on the written estimate rather than patching it.

Failed condensate pump. When the air handler sits below the drain exit, a small pump lifts the water out. Pumps burn out or jam, and the reservoir overflows onto the floor. We test the float and motor, and a pump swap is a straightforward same-visit repair on most models.

Frozen coil melting off. A coil that iced up from low refrigerant or weak airflow dumps far more water than the pan and line were sized for when it thaws. We read refrigerant pressures on our gauges and check the filter and blower, because clearing the drain without fixing the freeze just delays the next puddle.

Stuck or disconnected float switch. The safety float is supposed to shut the system down before the pan overflows. When it's wired wrong, stuck, or bypassed by a past tech, the AC keeps running and the pan keeps filling. We verify the float actually interrupts the circuit and reseat or replace it.

How we diagnose it

Trace the condensate path from the coil pan through the line to its outside termination, and find where the water is actually backing up.
Pull and inspect the air filter and read airflow, since a starved coil freezes and then floods on thaw.
Put refrigerant pressures and temperatures on the gauges to rule out a low charge causing the freeze.
Test the float switch and, where present, the condensate pump float and motor.
On homes with two systems, confirm which air handler is the source before opening anything up.

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

AC Leaking Water in Alamo: common questions

How fast can you get to Alamo for a ceiling that's already staining?

Alamo is one of our core cities and sits close to our San Ramon base, so an active leak usually gets same-day attention when we have the day's room. Water against drywall is time-sensitive, so tell us when you call that it's an active leak and we'll prioritize the routing.

Does Alamo's heat make condensate leaks worse?

Yes. The longer and harder a coil runs, the more water it produces, and Alamo sees genuinely hot afternoons in summer that keep systems cycling for hours. A marginal drain line that survives spring will often overflow during the first stretch of real heat, which is when most of these calls come in.

Will I need a whole new AC because it's leaking water?

Almost never. Water means a drainage problem, not a dead compressor. The usual fixes are a line clearing, a new float switch, a condensate pump, or a pan, all in the repair range. We charge $75 to diagnose, credited toward any repair over $200, and put the price in writing before we touch anything.

Nearby and related

AC Leaking Water near Alamo: Danville · Blackhawk · Lafayette · Walnut Creek .

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