For AC repair or a heating problem in Sunnyvale, Santa Clara or Cupertino, start with a diagnostic visit, not a quote for new equipment. A useful visit checks airflow, the thermostat, the capacitor and contactor, the condenser coil and the signs of a refrigerant problem before anyone mentions replacement. During a heat spell, a system that stops cooling is treated as urgent, especially an older one in a house that holds heat.
What we check on an AC repair call
Most no-cooling calls come down to a short list of causes, and the technician works through them in order:
- Filter and airflow. A clogged filter, closed vents or a weak blower starve the indoor coil and can freeze it.
- Thermostat demand. Confirming that the thermostat is really calling for cooling rules out settings, batteries and wiring first.
- Outdoor fan, capacitor and contactor. A failed capacitor or a worn contactor is one of the most common reasons an outdoor unit hums, clicks or will not start.
- Coil condition. Dirty condenser and evaporator coils cut cooling capacity on exactly the afternoons you need it.
- Refrigerant and compressor symptoms. Ice on the lines, warm air while the outdoor unit runs, or a compressor that keeps shutting off can point to a leak or a compressor fault. Those are confirmed with readings, not guessed.
If the system is fully down in hot weather, go to emergency AC repair; for everything else, start with AC repair. A yearly tune-up under a maintenance plan catches a weak capacitor or a dirty coil before the first hot week.
When a furnace problem can’t wait
No heat on a cold night, a burning smell that does not fade after the first run of the season, repeated ignition failures, short cycling or a safety switch that keeps tripping should all be checked quickly. Winters here are mild, but from November to March nights get cold enough that a furnace or heat pump runs every day. Furnace repair covers gas furnaces, and heat pump repair covers heat pumps, including ductless systems that heat as well as cool. If you smell gas, leave the house and call the gas utility or 911 from outside first.
Repair before replace
A failed capacitor, a thermostat problem, a clogged filter or an airflow restriction is ruled out before anyone talks about new equipment. When replacement does come up, it should be because of the system’s age, its repair history, parts that are no longer available, rising energy use or comfort problems that a repair will not solve. Parts are matched to the exact equipment: brand, model, age and warranty situation. The brands we service pages cover what changes from one manufacturer to the next, and new installation explains how a replacement is sized and planned.
The homes we work on
Many houses in Sunnyvale, Santa Clara and Cupertino were built from the 1950s to the 1970s with a forced-air furnace, ducts in the attic or crawlspace and central AC added later. Aging ducts are a common reason one room never gets comfortable. Eichler homes, best known in Sunnyvale and Cupertino, heat through radiant tubing in the concrete slab and have no attic, so cooling there usually means ductless mini-splits. Newer townhomes and condos keep the equipment in a compact closet with the condenser on a roof or balcony. Late summer and fall can bring wildfire smoke days, which is when indoor air quality work matters most. Offices, shops and restaurants are covered under commercial HVAC.
Local details for each city are on the Sunnyvale, Santa Clara and Cupertino pages.
How a visit works
- Call or book online. Phone lines are staffed 24/7. Tell us what the system is doing: no cooling, no heat, a noise, a smell, an error code.
- Diagnosis. The technician checks the symptom against the system: thermostat demand, airflow, electrical readings and safety controls.
- Findings before work. You get clear findings, your repair options and the cost factors before any work begins.
- Repair. Once you approve, the repair is made, and repairs are backed by a warranty covering both parts and labor.
Same-day service is available, and urgent no-cooling and no-heat calls get the earliest opening. We have served Sunnyvale since 2009 and hold a 4.9 out of 5 average rating across 328 reviews. Our technicians are EPA-certified, and we are independent, not affiliated with any equipment manufacturer.