The draft inducer motor is the small blower that runs for a few seconds before the burners light. Its job is to pull combustion gases through the heat exchanger and push them out the flue, establishing a safe draft so exhaust never spills back into the house. Only after a pressure switch confirms the inducer is moving air will the control board allow the igniter and gas valve to fire.
That safety interlock is why a failing inducer produces a no-heat furnace rather than a dangerous one: if the motor's bearings seize or the windings burn out, the pressure switch never closes and the furnace simply won't start, usually flashing an inducer or pressure-switch fault code. A motor on its way out often announces itself first — a loud hum, grinding, or rattling at the start of each cycle, or a blower that spins slowly or intermittently.
A replacement inducer typically runs $400 to $1,100 installed. The motor or full inducer assembly is $70 to $300 — more for OEM high-efficiency units — and labor makes up the rest, since the assembly is bolted into the combustion path and gasketed against leaks. Before condemning the motor, a careful technician checks the cheaper culprits that mimic it: a clogged condensate drain or blocked vent can trip the same pressure-switch fault, and on a condensing furnace that blockage, not the motor, is often the real problem.