Furnace repair in Sacramento typically costs $150 to $700. The most common repairs — hot-surface igniter replacement, flame-sensor cleaning or replacement, and thermocouple work — fall between $150 and $350. Inducer-motor or pressure-switch failures usually run $300 to $600. Blower-motor replacement on a mid-efficiency gas furnace lands around $500 to $900 depending on the model.
Sacramento winters are mild enough that most furnaces run relatively few hours per year, which is why properly maintained units often last 20 years or more. The worst failures tend to happen during the first significant cold spell of the season, when the system fires up after months of sitting idle — a pre-season tune-up in October catches most of these before they fail in January.
Heat-exchanger cracks are the one furnace failure where replacement usually wins over repair. A cracked heat exchanger is a carbon-monoxide hazard, and on a 15-plus-year-old furnace the cost to replace the exchanger often approaches the cost of a new high-efficiency unit.