AC Repair in San Mateo, CA
If your air conditioner quits, tell us what it's doing and a licensed contractor who covers San Mateo County will get in touch.
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San Mateo doesn't ask much of an air conditioner
Summer afternoons here average 73°F. That's mild enough that a lot of homes get through the year without running an air conditioner at all, and the ones that do run aren't working against much heat.
So when an AC here breaks, it's rarely a case of the unit worn out from a hard summer. Wind is more often the reason. San Mateo County has logged 266 damaging wind events over the past ten years, enough to loosen electrical connections or shake a cabinet panel loose on an outdoor unit. Hail is rare here and small when it happens, nine events in ten years with stones no bigger than a quarter inch, not the kind that dents a coil. If your AC has stopped working, it's worth checking what a storm might have loosened before assuming the unit itself gave out.
- 73°F
- the average summer afternoon it cools against
- 9 hail events
- in ten years, and hail bends the fins on outdoor coils
- 266 wind events
- in ten years, and wind drives debris into outdoor units
NOAA nClimDiv, 1991–2020 normals
A new air conditioner would save little on running costs in San Mateo County, so the repair decision comes down to the unit's condition.
Estimates for a typical San Mateo County home, compared with an older unit built to the previous federal minimum, from EIA household energy data, California fuel prices and NOAA climate normals. Your home will differ.
Repair makes sense when a part like a capacitor or contactor has failed.
Replacement makes sense when the compressor has failed or the system uses R-22 refrigerant, which is no longer made.
California requires HVAC contractors to hold a state license.
California licenses HVAC contractors through the Contractors State License Board. The license is issued to the contractor, not to each job, so nothing new is pulled for a repair like this one.
An air conditioner repair means opening the refrigerant side of the system. That work needs EPA Section 608 certification, a federal requirement that applies everywhere in the country. In California, that certification sits alongside the state license rather than replacing it, so a contractor working on your AC should hold both.
Sources: California Legislative Counsel · Contractors State License Board
- Why is my AC not blowing cold air?
- The most common cause is low refrigerant from a leak, or a dirty air filter choking off airflow over the coil. A frozen evaporator coil will also push air that feels weak or barely cool, and that's usually a sign one of those two problems has been going on for a while. Check the filter first, since that's the one thing you can rule out yourself. If it's clean and the air still isn't cold, the system needs a contractor to check refrigerant levels and look for the leak.
- Why is my AC leaking water?
- Most often this is a clogged condensate drain line, which backs up and sends water where it shouldn't go. Algae and dust build up inside that line over time and eventually block it. A dirty filter can also cause this indirectly, by freezing the coil, which then drips as it thaws. Clearing the line usually stops the leak, but if it keeps happening, a contractor should check the drain pan and the coil itself.
- Why won't my AC turn on?
- Start with the thermostat. Check that it's set to cool and the batteries aren't dead. If the thermostat looks fine, check the breaker for the AC, since a tripped breaker will keep the whole system from starting. San Mateo sees frequent damaging wind events, and those are a common cause of short power interruptions that trip breakers. If the breaker is fine and it still won't start, the capacitor or the contactor may have failed, and that's a job for a contractor to diagnose.