Condensate Leak in the Attic in Moraga

Condensate Leak in the Attic in Moraga

Moraga sits in a valley between Lafayette and Orinda with cool, foggy mornings and warm afternoons that climb into the 80s, occasionally mid-80s on the hot days. That afternoon heat runs the AC enough to produce steady condensate at the coil, and on the 1960s through 80s ranches around town the air handler is often up in the attic, draining by gravity through a PVC line. When that line clogs, the water has nowhere to go but the emergency pan, and from there the ceiling.

The morning fog and afternoon swing feed the problem a little. Coils that cycle through humid mornings stay damp, and damp drain lines are where algae and sludge grow. Over a season that biofilm narrows the pipe until one warm week it plugs entirely. The secondary pan and float switch are the last defense, and on older ranch installs those parts are frequently original.

Almost every version of this is a small repair. A clogged line gets cleared and flushed. A stuck float or a corroded pan is an inexpensive part. The costly outcome is the leak nobody caught, where the stain becomes a soaked ceiling. We find the real cause before we quote, and on Moraga's hillside lots we scope attic access carefully so the plan is concrete before we start. The $75 diagnostic gets credited toward the repair if it runs over $200.

Common causes

Algae-clogged primary drain line. Damp coils from foggy mornings keep the drain wet, and biofilm grows until the line plugs. We clear it with a vacuum at the termination, flush from the coil, and confirm the full run carries water freely.

Emergency pan filling under the attic handler. The secondary pan is a backup. Water sitting in it means the primary path already failed. We treat the full pan as the warning it is, clear the actual clog, and inspect the pan for rust-through before closing the call.

Float switch not cutting the system. The safety float is supposed to stop the AC before the pan overflows. When it is missing, stuck, or wired around, nothing halts the leak. We test it by floating it by hand and watching the system shut down. If there is no switch, the cost of adding one goes on the estimate.

Cracked or corroded primary pan. On a 30-plus-year-old ranch unit the coil pan rusts or cracks and lets water bypass the drain entirely. We inspect with a light and mirror and replace a compromised pan, since patches on a coil pan do not last.

Improper slope on the drain run. Condensate drains by gravity, so a flat or sagging line pools and overflows. We check the pitch with a level and re-hang the run to fall steadily toward the termination.

Loose or disconnected drain fitting. Glue joints let go over the years and dump condensate into the attic. We trace the run, find the open joint, and re-cement it so the water goes where it should.

How we diagnose it

• Scope attic access on the hillside lot, then locate the real water source before opening the system.
• Test the float switch by hand to confirm it shuts the AC down as designed.
• Vacuum and flush the primary line end to end and verify a clean run at the termination.
• Inspect the primary and secondary pans for cracks and corrosion with a light and mirror.
• Check the drain-line slope and re-pitch any flat or sagging sections.

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

Condensate Leak in the Attic in Moraga: common questions

Nearby and related

Condensate Leak in the Attic near Moraga: Orinda · Lafayette .

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