An inducer motor on a furnace is a motor that operates the inducer assembly, which is a small fan that pulls heat through the furnace and distributes it to the outside venting. The assembly is typically made of metal or plastic, depending on the AFUE percentage of the furnace.
The inducer assembly creates a draft through the furnace, which closes the pressure switch and creates the suction of the vent. All parts of the inducer assembly must be working correctly, or the furnace will not function correctly. A malfunctioning inducer motor is a safety risk due the potential carbon monoxide build-up. As of 2015, repairs to the inducer motor are typically between 500 to 800 dollars.