Furnace Repair
San Jose, CA

Most San Jose homes rely on forced-air gas furnaces — the housing stock from the 1960s through 2000s across Willow Glen, Cambrian, Almaden Valley, and Evergreen was almost universally built with 80% AFUE gas furnaces connected to central ductwork. Many of these original units have been replaced once or twice, but we still encounter 20-year-old furnaces in homes throughout South San Jose and the Blossom Hill corridor that are on their last legs.

Newer construction in North San Jose — the Berryessa and Milpitas border area — tends toward 96%+ AFUE condensing furnaces or heat pump systems. These high-efficiency units are more complex and require technicians who understand condensate traps, dual heat exchangers, and variable-speed blower motors. That’s us.

Furnace Problems We Fix Most Often in San Jose

Ignitor failure: The #1 furnace repair call in our service area. Hot surface ignitors are consumable parts that crack after 5–8 years of thermal cycling. When the ignitor fails, the gas valve opens but the burner doesn’t light — the furnace locks out after 3 attempts and blows cold air. Repair: $150–$350 including the part. We carry ignitors for Carrier, Lennox, Trane, Rheem, and Goodman on the truck.

Flame sensor issues: The flame sensor confirms the burner is lit. When it corrodes (common in San Jose’s moderately humid winters), the furnace lights briefly then shuts off within 5–10 seconds. Often just needs cleaning with fine emery cloth — $100–$200. Replacement if worn: $150–$300.

Blower motor failure: Variable-speed ECM motors in newer furnaces last 15–20 years but cost significantly more to replace than old PSC motors. ECM motor replacement: $500–$1,200. Single-speed PSC motor: $300–$600. We diagnose whether it’s the motor, the capacitor, or the control board before recommending the repair.

Cracked heat exchanger: The most serious furnace issue. A cracked heat exchanger can leak carbon monoxide into your home. We see this in furnaces 15–25 years old across San Jose. If confirmed cracked, the furnace must be shut down immediately. Heat exchanger replacement: $1,500–$3,000. On furnaces over 18 years, a full system replacement ($4,500–$9,000) is usually the better investment.

Thermostat wiring and control issues: DIY smart thermostat installations that weren’t wired correctly, or older mercury thermostats that drift out of calibration. We trace the full control circuit before replacing parts. Fix: $100–$400.

Furnace Brands We Service in San Jose

Carrier, Lennox, Trane, Rheem, Goodman, Bryant, American Standard, York, Ruud, Daikin, Amana, Coleman, and all other residential gas and electric furnace brands. No brand restrictions.

Prices are estimates for San Jose residential furnace repair. Actual cost depends on furnace type, age, brand, and parts availability. We provide exact pricing before any work begins.