AC Not Cooling

Start outside. If the fan on top of the condenser is spinning but the unit sounds like it is straining, and the copper line coming out of it is not cold, the system is not moving heat. On a unit under about a decade old that is most often a low charge from a small leak, and the leak is the repair — a recharge without finding it is a payment plan, not a fix.

Ice is a symptom, not a cause. A frozen line set or a frozen indoor coil means airflow or charge, and the useful move is to switch the system to fan only and let it thaw before anyone looks at it. A photograph of the ice is genuinely useful; running the compressor into it is how a $400 call becomes a compressor.

Check the obvious in this order and photograph what you find: the thermostat display, the breaker for the condenser, the switch on the wall by the furnace or air handler that looks like a light switch, and the condensate pan under the indoor unit. A full pan trips a float switch that kills the system deliberately — it is protecting your ceiling.

If the breaker trips again immediately after being reset, stop resetting it. A dead short in a condenser is a hazard and repeated resets are what turns it into a fire.

• Under ~12 years: parts are worth it. A capacitor, a contactor, a fan motor, a control board — these are ordinary repairs on a system with life left.
• 12 to 15 years: it depends on which part and what else is tired. This is where a straight assessment is worth more than a cheap one.
• Over ~15 years, or any compressor failure, or an R-22 system with a leak: you are in the replacement conversation whether or not anyone says so.

Local published figures: a diagnostic visit at $69 at one San Jose shop, with a minimum labor charge of $199 and AC repairs quoted from $199 before parts. Thermostat replacement runs $199–$299 installed. Replacement equipment is a different order of magnitude — Bay Area contractors publish $7,000–$12,500+ for a condenser-and-coil replacement and $12,000–$20,000+ for a furnace-and-AC pair, and the cost guide breaks down what moves you inside those bands.

The outdoor unit whole, its data plate close enough to read the model and serial, the indoor unit and its plate, the thermostat display, and the breaker panel with the door open. Add one line about when it started and whether anything else in the house changed — a new panel, a remodel, a filter that has been in longer than anyone wants to admit.