Inducer motor assembly. This assembly is designed for 40, 60, 80, and 100 thousand BTU model furnaces. Your furnace's BTU rating may be listed on the model number tag. You can also determine the rating from your model number—the 3-digit number preceding the hyphen indicates the BTU rating.
Carrier furnace circuit board. This circuit board regulates the supply of power to the furnace components.
Furnace draft inducer motor. The draft inducer motor draws air into the burner and exhausts it out the flue. If the draft inducer motor is defective, the furnace may not heat.