AC Leaking Water in Alameda

AC Leaking Water in Alameda

An AC system makes water on purpose. As warm indoor air passes over the cold evaporator coil, moisture condenses out and drips into a pan, then runs off through a drain line. When you see water on the floor near the indoor unit, that normal condensate is not getting where it should. It is overflowing, backing up, or pouring out of a pan that has rusted through. None of that means your system is dead. It almost always traces to one clogged line, one cracked pan, or one stuck float switch.

Alameda sits right on the Bay, so cooling load is light and the marine layer keeps humidity up. That combination matters here. A system that runs short cycles on a mild day still pulls moisture, and slow-draining condensate has plenty of time to grow the algae and slime that clog a drain line. Many island homes, especially the older Victorians and Craftsmans retrofitted with ductless or closet air handlers, route condensate through a long, low-pitched line or a small pump, and either one clogs.

The salt air adds a second problem. Drain pans and the metal around them corrode faster on the island than they do inland, so an older galvanized or steel pan can rust through and leak even when the drain line is clear. We sort out which one you have before we quote anything.

Common causes

Clogged condensate drain line. This is the leading cause on the island. Algae and biofilm build up inside the drain line and back the water up into the pan until it overflows. We clear the line with a wet vac at the termination and flush it through, then confirm the water runs free. If there is a cleanout tee we add a treatment tab so it stays clear longer.

Cracked or rusted-through drain pan. Alameda's salt air corrodes metal pans faster than inland. An older steel pan can rust at the seams and leak even with a clear line. We inspect the pan, and if it is the secondary pan we can sometimes replace just that. If it is the primary pan under the coil, that is a bigger job and we put the real number on the estimate.

Failed condensate pump. Closet and basement air handlers in the older homes often can't drain by gravity, so they use a small condensate pump. When the pump motor or float fails, water backs up and spills. We test the pump by filling the reservoir, and if it won't kick on we replace it. It is a common, inexpensive part.

Stuck or failed float switch. The safety float switch is supposed to shut the AC off when water rises in the pan. When it sticks open the system keeps running and floods; when it sticks closed your AC won't start at all. We test the switch and replace it if it is not breaking and making the circuit correctly.

Frozen evaporator coil that melts off. If the coil ices up from low refrigerant or weak airflow, it sheds far more water than the pan was built for when it thaws, and the overflow looks like a leak. We check the filter, the blower, and refrigerant charge. On Alameda systems a low charge often points back to a corroded coil leaking at a fitting.

How we diagnose it

• Pull and inspect the filter and confirm airflow across the coil, since restricted airflow drives both freezing and overflow.
• Inspect the primary and secondary drain pans for rust, cracks, and standing water, paying attention to corrosion from the salt air.
• Clear and flush the condensate drain line, then watch it drain to confirm the clog is gone.
• Test the condensate pump and the float safety switch under load to see which one failed.
• Read refrigerant pressures and coil temperature to rule out a frozen coil and a corrosion leak behind it.

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

AC Leaking Water in Alameda: common questions

Nearby and related

AC Leaking Water near Alameda: Oakland · San Leandro · Berkeley .

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