What furnace repair costs, part by part.

Flame sensor — roughly $80–$250. This is the single most common furnace fault and the cheapest real repair. The sensor is a thin metal rod that confirms a flame is actually present; when it gets coated in residue, the furnace lights and then shuts down after a few seconds as a safety measure. Cleaning or swapping it is quick work, and it is also the classic cause of a furnace that keeps short-cycling — starting, running briefly, then giving up and retrying. It is also the leading cause of a furnace that blows cold air — the burner lights, the sensor fails to confirm the flame, the gas shuts off, and the blower keeps pushing unheated air until the next attempt.

Igniter — roughly $150–$350. The igniter glows hot to light the gas, and it wears out on a predictable schedule — usually every 4–7 years. A furnace that hums and tries but never lights is very often this. The part itself is inexpensive; most of the cost is the visit. If the furnace is completely dead rather than just misfiring, our furnace not turning on guide covers the free checks — thermostat, breaker, power switch, furnace door — worth working through before a service call is booked.

Capacitor or relay — roughly $150–$400. Small electrical components that start and run the blower. They fail suddenly and without warning, which is why a furnace can be fine one day and dead the next.

Blower motor — roughly $400–$900. If air isn't moving even though the burners light, the blower is the usual suspect. Variable-speed motors sit at the top of that range.

Control board — roughly $400–$900. The furnace's brain. When it fails you often get erratic behaviour, blinking error codes, or a system that ignores the thermostat entirely.

Heat exchanger — roughly $1,000–$2,500, and the decision point. This is the metal chamber separating combustion gases from the air you breathe. A cracked one can leak carbon monoxide, so a technician will red-tag and shut down the furnace rather than leave it running. On a furnace over about 12 years old, this repair usually costs enough that replacement is the better use of the money — especially since a crack often signals the rest of the unit is equally tired.

The rule of thumb that actually works. Multiply the repair quote by the age of the furnace in years. If the result comfortably exceeds the price of a new system, replace it. Under that, repair. A modest repair on a nine-year-old furnace is easy math; a major one on an eighteen-year-old furnace almost never is — the new-furnace price guide breaks down what actually moves the number so you can run the comparison against your own quote fairly.

The same fault-by-fault approach applies to the cooling side, with a different parts list and a different failure calendar — our Spokane AC repair page covers what each common air-conditioner fault typically costs to fix and which ones are the cheap ones to catch first. And if your home heats with a heat pump rather than a gas furnace — increasingly common in newer Spokane builds — the parts list changes again, with reversing valves, defrost boards and outdoor fans doing most of the failing; our Spokane heat pump repair page covers what each of those typically costs to fix.

Labor rates and permit fees also vary across Spokane County — what a job costs in Cheney or Mead can differ from rates closer to the city center. The Spokane County service areas page notes the differences by town.