AC Repair in San Jose

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Most San Jose air conditioners do not fail on a mild June morning. They fail on the third afternoon of a heat wave, when the system has been running flat out for days and a weak capacitor, a dirty coil or a slow refrigerant leak finally gives up. This page is about getting the system you already own working again: what usually goes wrong here, what you can safely check yourself, and how our technicians diagnose the fault before anything is replaced.

Cool Aid Air Conditioning & Refrigeration has repaired air conditioners around the South Bay since Glenn McKinny founded the company in 1966. We work from 3511 Thomas Rd in Santa Clara, right next to San Jose, and our technicians hold EPA Universal certification under our CA C-20 license. If you want the wider view of what we do across the city, start at our San Jose HVAC and refrigeration hub.

Why San Jose air conditioners break when they do

San Jose summers are hot and dry, with heat waves that push an AC into long run cycles it rarely sees the rest of the year. That pattern shapes the repair calls we get.

• Heat-stressed electrical parts. Run capacitors and contactors in the outdoor unit wear out with heat and hours. A failing capacitor often shows up as a humming outdoor unit with a fan that will not spin.
• Smoke and dust on the coils and filter. In seasons when wildfire smoke drifts into the valley, filters load up far faster than normal. A choked filter starves the indoor coil of air, and the coil can freeze into a block of ice.
• Slow refrigerant leaks. A system that cooled fine last year but struggles now may be losing refrigerant. Topping it up without finding the leak just postpones the next call.
• Attic ducts and air handlers. Many homes in Willow Glen, Cambrian and West San Jose have ducts running through hot attics. Disconnected or crushed runs leave one end of the house warm no matter how long the system runs.

What you can check before you call

A few checks are safe for any homeowner and sometimes solve the problem outright:

• Confirm the thermostat is set to Cool, the set point is below room temperature, and the batteries are fresh if it uses them.
• Look at the breaker panel for a tripped AC or air handler breaker. Reset it once. If it trips again, leave it off and call, because a repeat trip points to an electrical fault.
• Pull the filter. If it is gray and matted, replace it, especially after a smoky week.
• If you see ice on the indoor coil or the copper line at the outdoor unit, switch the system to Fan only (or off) and let it thaw for a few hours before running it again.
• Clear leaves, weeds and stored items from around the outdoor unit so it can move air.

How we diagnose an AC repair

Our approach is to measure before we recommend. On a typical repair visit a technician will:

• Talk through what you have noticed: when it started, whether it is the whole house or a few rooms, and any noises or smells.
• Check thermostat wiring and control voltage so we are not chasing a symptom.
• Test capacitors, contactors and motors in the outdoor unit with a meter rather than guessing.
• Read system pressures and temperatures to see whether the refrigerant charge and airflow make sense together.
• Inspect the indoor coil, drain line and accessible ductwork for blockages, leaks and disconnections.
• Explain the fault in plain terms and give you the repair options before any work starts.

We service the major brands found in San Jose homes, including Daikin, Amana, Goodman, York, Trane and Carrier. For more on how our residential repairs work in general, see our residential HVAC repair services page.

Refrigerant questions come up a lot

Older San Jose systems may still run on R-22, which is no longer produced, so a leak on one of those units becomes a bigger decision. Most systems from the last fifteen years use R-410A, and new equipment is moving to lower-GWP refrigerants such as R-32 and R-454B. Our technicians are trained on these newer refrigerants, which matters if a repair involves a recently installed unit. Whatever the refrigerant, we look for the leak rather than simply recharging.

When a repair turns into a replacement

Sometimes the honest answer is that the repair costs too much relative to the age of the system, or that the refrigerant makes future repairs impractical. When that happens we say so and leave the choice to you. Note that replacing an AC in a San Jose single-family home or duplex generally needs a city mechanical permit, plus an electrical permit if circuits or the panel change (City of San José). That is one reason replacement is a planned project, covered on our San Jose AC installation and replacement page. If you are weighing a switch away from gas as well, read about heat pump installation in San Jose.

For typical repair costs in the city, we keep a separate San Jose AC repair cost guide. If you are still deciding who to call, our article on choosing an AC repair company in San Jose lists the questions worth asking any contractor, including us.

Keeping it from happening again

A spring tune-up before the first heat wave catches most capacitor, coil and drain problems while they are still cheap to fix. It is also the time to swap filters and check that the outdoor unit is clear. See HVAC maintenance in San Jose for what a visit covers. If your AC quits late at night during a heat wave and someone at home is vulnerable to heat, our emergency HVAC repair service runs 24/7.

Every repair we complete carries a 1-year parts and labor warranty.

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Frequently asked questions

Written and reviewed by Jim McKinny, owner of Cool Aid Air Conditioning & Refrigeration — California C-20 and C-38 licensed, EPA Universal certified, second generation of a family business serving the Bay Area since 1966. Every job we complete is backed by our 1-year parts & labor warranty.