When an air conditioner in Tiburon stops cooling, the cause is usually tied to how it lives here. Bay breezes keep it off for most of the year, and the outdoor unit spends those months in salt air, fog and wind. Then a sunny afternoon heats up the rooms with Angel Island views, the system is asked to run for hours, and whatever weakened while it sat idle gives out. The good news is that most of these failures come down to a single part, not a dead system.
What usually fails in a peninsula AC
| What you notice | Likely cause here | What it usually takes |
|---|---|---|
| Outdoor unit hums, fan does not turn | Capacitor weakened over the idle months, or a fan motor with a seized bearing | Capacitor or fan motor replacement |
| Nothing happens at all | Pitted contactor, corroded wire terminals, a tripped breaker or dead thermostat batteries | Electrical testing and the failed part |
| Runs, but the air is barely cool | Outdoor coil coated with salt and grime, or a slow refrigerant leak | Coil cleaning, or a leak search and repair |
| Oily spots on the copper or the coil | Refrigerant leak, often where corrosion has eaten through | Leak repair or a coil replacement |
| Water around the indoor unit | Condensate drain blocked after months without use | Drain clearing and a float switch check |
| Main rooms cool, the view rooms do not | Afternoon sun on west glass beyond what the ducts or zone deliver | An airflow and zoning check rather than a part |
The last row matters. A system can be in perfect working order and still lose to a wall of west-facing glass at four in the afternoon. We measure before we call it a failure, and if the real issue is the duct design or the size of the system, we tell you that instead of selling a repair.
How we diagnose it
The visit follows the order that keeps you from paying for the wrong fix. We check the thermostat and the filter, then airflow across the indoor coil, then the electrical side under load: capacitor values, contactor, connections and motor amps. Only then do we put gauges on the refrigerant side. If the charge is low, there is a leak, and adding refrigerant without finding it just postpones the next call. On coils damaged by salt, we show you the corrosion so you can see why we recommend what we do.
We repair all major AC brands. Our technicians are EPA-certified to handle refrigerant, repairs carry a 90-day warranty, and replacement parts keep the manufacturer’s warranty.
What it costs
Most AC repairs cost $150–600. A capacitor replacement is usually $150–300, and a refrigerant recharge, once the leak is fixed, $200–400. A failed coil or compressor costs more, and that is the point where we price a replacement alongside the repair so you can compare. You get the price after the diagnosis and before any work begins, and same-day visits carry no overtime charges.
Repair or replace?
Repair when one part failed and the system otherwise cools well. Consider replacement when a salt-damaged outdoor coil is leaking, when the system still uses R-22, which is no longer produced, or when it has needed several repairs in a few years. In a town where heating matters more than cooling, the replacement is often a heat pump rather than a new AC; if you prefer central air, see AC installation in Tiburon.
Before you call
- Set the thermostat to Cool, a few degrees below room temperature, and replace weak batteries.
- Swap a gray, clogged filter.
- Check the breakers and the outdoor disconnect.
- Look for a full drain pan or a tripped float switch near the indoor unit.
If the outdoor unit hums without the fan turning, switch the system off: running it that way can damage the compressor.
Keeping it from happening again
A spring AC tune-up cleans the coil, tests the capacitor and catches corrosion before the warm days. The general AC repair page goes deeper into each fault, and the Tiburon service area page lists the rest of our work in town.