An outside unit that hums while the fan stays still is the classic summer service call in Palo Alto, CA, and the cause is usually a failed run capacitor. That inexpensive component starts the compressor and fan, fades for years without complaint, and then quits under peak load. It is far from the only suspect, though. Contactors pit and stop passing clean power, condenser fan bearings dry out, small refrigerant leaks drain away cooling capacity, and evaporator coils ice over when a clogged filter strangles airflow.
Warm air from the vents can mean a failed capacitor, a refrigerant leak, a frozen coil, or a duct problem, and each one comes with a very different price to fix. That is why Palo Alto HVAC tests before touching anything. We meter capacitors against their microfarad rating, compare compressor and fan amp draws to the data plate, judge the refrigerant charge by superheat and subcooling instead of pressure alone, and inspect the coil, blower wheel, and filter whenever there is ice. Topping off refrigerant without locating the leak only buys cold air until the charge leaks out again.
Central air, heat pumps running in cooling mode, and ductless mini splits from every major brand are all in our wheelhouse. Because our trucks carry capacitors, contactors, fan motors, hard-start kits, and condensate pumps, most AC repairs are completed the same visit. If the compressor has failed on an older system, we tell you so directly and show you the numbers on repairing versus replacing. Call (650) 220-0821 and we will get cold air flowing in your Palo Alto home again.
For winter breakdowns, see Furnace Repair in Palo Alto.
How Much Does AC Repair Cost in Palo Alto?
Most air conditioner repairs in Palo Alto land between $150 and $650. Small electrical parts like capacitors and contactors sit at the low end, while refrigerant leaks, coils, and compressors cost more. You'll get an upfront quote from Palo Alto HVAC before we touch a single part.
| Repair | Typical cost | What it usually means |
|---|---|---|
| Capacitor replacementThe most common AC failure; outdoor unit hums but won't start | $150–$400 | Most common repair, usually same visit |
| Contactor replacementWorn relay that stops the condenser from starting | $150–$350 | Worn relay that stops the condenser from starting |
| Condenser fan motorOutdoor fan stops, compressor trips on high heat | $300–$700 | Fan won't spin, unit overheats and shuts down |
| Refrigerant leak repair + rechargeVaries with where the leak is and how much charge is lost | $300–$1,500 | Depends on leak location and refrigerant type |
| Evaporator coil replacementCorroded or leaking indoor coil | $1,000–$2,500 | Major repair; worth weighing against replacement on older systems |
| Compressor replacementLargest single repair; often weighed against a new system | $1,500–$3,000 | On systems past 10–12 years, replacement usually makes more sense |
Typical ranges for common repairs. Your exact price is quoted after diagnosis.
What Affects the Price
- The age of the system and whether parts are still readily available
- The type of refrigerant, since older R-22 systems cost far more to recharge
- Whether the repair is urgent, after hours, or can be scheduled
- Access to the equipment, like rooftop units or tight attic air handlers
When a quote climbs toward the cost of replacement on an older unit, we'll lay out repair and replacement prices together, with no pressure either way. Questions about cost? Call (650) 220-0821.
Warning Signs for AC Repair
Spotting the early warning signs gives you the chance to act before the situation spirals into something far more expensive. These are the signals our technicians see most often when a problem is underway:
- An AC that turns on and off every few minutes but never cools down the house
- Room-temperature air from the registers even though the AC is running
- A hiss or gurgle from the lines, a common sign of leaking refrigerant
- Cooling bills climbing while the house stays sticky and warm
- Clicking or humming outside with no fan movement
- Water dripping from the indoor unit or showing up on the ceiling below
- Ice on the refrigerant lines or a frozen indoor coil
- A burning smell or repeated breaker trips when the AC starts
Don't Wait for a Total Failure
A failing capacitor, clogged condensate drain, or dirty flame sensor rarely fixes itself and usually gets more expensive to address the longer it runs. Call Palo Alto HVAC at (650) 220-0821 at the first sign of trouble.
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Get Help: (650) 220-0821AC Repair FAQ
Why Professional AC Repair Matters
An air conditioner puts several hazards into one cabinet. The capacitor can deliver a painful shock long after the breaker is off, the condensing unit is wired for 240 volts, and the refrigerant circuit is a sealed, pressurized loop that federal rules forbid venting. Servicing it properly takes gauges, a recovery machine, and a vacuum pump, not a DIY recharge can. Diagnosis has its own traps. A frozen coil is as likely to be an airflow issue as a charge issue, and recharging a system that still leaks throws money away while moisture and acid work on the compressor.
What you get from a pro is a repair that holds. Our experienced technicians find leaks with dye and electronic detectors, base every charge decision on superheat and subcooling, test electrical parts with a meter before condemning them, and measure static pressure and inspect the blower and filter whenever airflow is in question. Parts-cannon fixes tend to bring you back in a few weeks. Ours are built to last through the heat. And if the numbers say replacement is the better call, we show you those numbers honestly, without pressure.
What to Expect From Our AC Repair
Our systematic workflow delivers thorough, lasting results on every job. Here's how we handle AC repair from start to finish:
System Diagnosis
Before we replace anything, we meter the electrical components, read the refrigerant charge with superheat and subcooling, and look over the coil, filter, and condensate line for the actual cause.
Findings & Firm Quote
Nothing happens without your approval. We explain what broke and why, quote a firm price, and, if the compressor or coil has failed, walk you through the repair-or-replace decision honestly.
Same-Visit Repair
Our trucks carry capacitors, contactors, fan motors, and the other parts that fail most in summer, so the large majority of AC repairs are completed on the spot.
Test Under Load
Before we leave, we measure the temperature split, recheck amp draws and refrigerant charge, flush the condensate line, and run the system through a complete cooling cycle.
Want a Professional Opinion?
We provide honest advice and upfront pricing on all AC repair work.
Get Help: (650) 220-0821AC Repair Prevention Tips
A little routine maintenance goes a long way toward avoiding a mid-season breakdown. Follow these tips from our experienced technicians:
- Have the AC serviced every spring, ahead of the first real heat
- Shade helps, but never enclose the outdoor unit; it needs free airflow on all sides
- Listen for new buzzing or clicking at startup, the classic sound of a dying capacitor
- Change the filter monthly during cooling season; starved airflow is how coils freeze
- Hose off the condenser coil every spring and trim plants to at least two feet away
- Avoid shutting registers in unused rooms, which raises static pressure and stresses the blower
- Start each cooling season by flushing the condensate line so algae cannot block it
Comparing DIY and Professional AC Repair
Some simple checks are suitable for DIY, but most heating and cooling repairs benefit from professional tools, training, and experience. Here's a comparison:
| Factor | DIY Attempt | Professional Service |
|---|---|---|
| Refrigerant | Adding refrigerant while it keeps leaking | Leak repaired and correct charge restored by weight |
| Electrical Safety | Risk of shock from 240V and stored charge | Capacitors drained, power confirmed off |
| Frozen Coils | Thawed and refrozen on repeat | Airflow or charge problem identified and fixed |
| Diagnosis | Guessing between look-alike faults | Meters, gauges, and temperature clamps |
| Parts | Whatever capacitor or motor fits | Ratings matched to the data plate |
| Outcome | Short-lived relief | Fix proven under full cooling load |
Talk to a AC Repair Expert
Don't let a failing system get worse. Call Palo Alto HVAC now for prompt, professional service.
Get Help: (650) 220-0821AC Repair Across the Palo Alto Area
Our technicians handle AC repair throughout Palo Alto and the surrounding communities, with the same upfront pricing everywhere we work.