AC Leaking Water in Martinez
Your AC is supposed to make water. The evaporator coil condenses humidity out of the air, and that water drains down a pan and out a PVC line. When it ends up on the floor instead, the drainage path failed somewhere. It is rarely the compressor or anything catastrophic. A clogged line is the usual cause, with a full pan, a bad float switch, or a frozen coil behind it.
Martinez sits on the Carquinez Strait, so mornings here tend to run more humid than the dry inland Diablo Valley cities further from the water. When the air carries more moisture, the coil pulls more condensate, and more condensate moving through the drain line gives algae more to feed on. The older tract homes around town typically run the air handler in a hall closet or the attic, draining through a line that has had decades to collect gunk.
The repair is almost always small. We are clearing a line or replacing a cheap part, not condemning a system. What we do not want is a slow leak running into closet flooring or a ceiling for a week before anyone notices. If you see water, kill the system at the thermostat and call. The diagnostic is $75, credited toward any repair over $200.
Common causes
Clogged condensate drain line. The leading cause, and the more humid air off the Strait gives the algae that plugs the line a little more to work with. Water backs up in the pan and overflows. We vacuum the line at the outdoor end, blow it clear, and flush it, then confirm water runs all the way through.
Overflowing or cracked drain pan. Decades-old galvanized pans in closet and attic handlers rust through at the seams. Once the pan leaks or its drain clogs, water hits the floor. We inspect the pan, clear its drain, and replace it if corroded. We always check upstream too, since a full pan usually started with a blocked line.
Failed float switch. The safety switch that should shut the AC off when the pan fills can stick or fail. If it fails closed, the system keeps overflowing. We test it, confirm it interrupts the cooling call, and replace it if it is not working. Cheap part, prevents real water damage.
Frozen evaporator coil. A dirty filter or low refrigerant ices the coil, and the melt overruns the pan when the unit cycles off. We check the filter and blower airflow first, then read refrigerant pressures with gauges. We diagnose the cause of the freeze rather than just topping off refrigerant.
Slipped or disconnected drain fitting. PVC joints in an attic that heats up all summer can loosen or separate, dumping condensate beside the unit. We trace the full drain run, find the break, and re-glue or replace the fitting so the water goes outside where it belongs.
How we diagnose it
- Shut the system down and identify exactly where the water originates: primary pan, secondary pan, or the line.
- Inspect the air filter and check blower airflow, the usual suspects behind a frozen coil.
- Clear and flush the condensate line, then pour test water through the pan to confirm drainage all the way out.
- Test the float switch to confirm it shuts the system off when the pan fills.
- Read refrigerant pressures with gauges if there is any frost or weak cooling.
$75 diagnostic, credited toward any repair over $200. You get a written quote before any work begins.
AC Leaking Water in Martinez: common questions
Do you come out to Martinez, or only the Tri-Valley?
Does the humidity here make leaks more likely?
The AC still cools but there is water under it. Is that bad?
Nearby and related
AC Leaking Water near Martinez: Concord .
This is usually a ac repair in Martinez job. See our ac repair overview or the Martinez service area.
AC Leaking Water in Martinez
Free on-site assessment, written the same day.
Bay Area · 7am–7pm · 7 days · no overtime charges