Condensate Leak in the Attic in Cupertino

Condensate Leak in the Attic in Cupertino

Cupertino sits in the South Bay, where summer cooling load is lighter than what we see inland in the Tri-Valley. That means less condensate on a typical day. But a lot of Cupertino's housing is older single-story ranch stock now on its second round of equipment, and the original attic air handlers and drain pans in those homes are old enough to fail on age alone.

A condensate leak in a Cupertino attic almost always traces back to one part, not a dead system. Often it's a metal pan that corroded through after a couple of decades, a clogged line, or a missing float switch that should have shut the unit down before water ever reached the ceiling. The cooling side of the system is usually still healthy. What gave out is the cheap drainage hardware around it.

Most homeowners we visit in the older Cupertino tracts want the leak diagnosed properly rather than patched. When we find a corroded pan on an aging air handler, that's also the honest moment to talk about whether the whole unit is near replacement, since a system that old is hitting the end of its service life anyway.

Common causes

Corroded or cracked primary drain pan. On Cupertino's many aging attic systems, the metal pan rusts through or the plastic one cracks, and water bypasses the drain. We inspect the pan with a light and mirror under the coil. If it's gone, replacing it means pulling the coil, so we price it clearly on the estimate and tell you how the cost compares to a full air handler swap given the system's age.

Clogged primary condensate line. Even with lighter cooling load, algae and dust still build up over years and choke the drain. The water backs up into the pan and overflows. We clear it with a wet vac and compressed air, flush it, and confirm free flow to the termination.

Missing float switch on an older install. Many Cupertino ranches were installed before float switches were standard, so there's nothing to shut the system off when the pan fills. We add one and test it by raising the float to confirm the unit cuts out. It's a small part that prevents the ceiling damage entirely.

Failed condensate pump. Where the attic drain can't run to gravity, a small pump lifts the water out, and those motors and floats fail with age. When the pump quits, the pan fills fast. We test it under power, check the check valve, and replace it if it's done.

Flat or reverse-sloped drain line. Some original installs ran the line dead flat or slightly uphill, so water sits and grows clogs instead of draining. We check the slope and, if needed, re-pitch the line or add an access tee so it actually drains and can be flushed in the future.

How we diagnose it

• Inspect the attic air handler, primary pan, and emergency pan, paying close attention to corrosion on older metal pans.
• Trace the ceiling stain back to the failure point at the unit.
• Test the float switch, or add one if the older install never had it.
• Clear and flush the primary drain line and verify free flow to the termination.
• Check pan slope and the condensate pump if present, and note the air handler's age and condition on the estimate.

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

Condensate Leak in the Attic in Cupertino: common questions

Nearby and related

Condensate Leak in the Attic near Cupertino: Sunnyvale · Saratoga · Los Altos .

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