The Role of a Furnace Inducer Motor

Gas furnaces feature dozens of parts. While you might be familiar with some of these parts, such as the burner assembly and heat exchanger, you might be unfamiliar with the inducer motor. Nearly all modern gas furnaces have an inducer motor. It plays an important role in both the safety and performance of gas furnaces.

What Is a Furnace Inducer Motor?

Also known as a draft inducer motor, a furnace inducer motor is a type of blower that’s designed to remove any lingering gases in the heat exchanger of a gas furnace. They are available in different types. Most inducer motors, however, consist of a propeller-bladed motorized fan with a built-in electrical box.

To generate heat, your furnace must burn natural gas. This combustion process will occur inside of your furnace’s heat exchanger. The burner assembly will ignite natural gas, resulting in flames inside of the heat exchanger. The inducer motor is responsible for purging and removing the byproduct gases from the heat exchanger after combustion has occurred.

Combustion gases occur in all gas furnaces. While they are contained to the heat exchanger, they must be removed. The inducer motor is designed to remove combustion gases.

How Furnace Inducer Motors Work

Inducer motors are designed to turn on automatically at the beginning of each heating cycle. Before the burner assembly ignites the gas, the inducer motor will turn on. It will receive voltage from the built-in electrical box, which turns on the inducer motor.

Upon turning on, the inducer motor will force air through the interior of your furnace’s heat exchanger. It’s essentially a ventilation component. As the inducer motor’s blades spin, any lingering combustion gases in the heat exchanger will be removed. The combustion gases will be pushed out of the heat exchanger and, thus, safely exhausted outside of your home.

Signs of a Failing Furnace Inducer Motor

How do you know if your furnace needs a new inducer motor? Your furnace may produce less heat with a bad inducer motor. Gas furnaces produce heat by burning natural gas inside of the heat exchanger. The presence of lingering combustion gases from a prior heating cycle will interfere with this process.

You may hear strange noises coming from your furnace if it has a bad inducer motor. Inducer motors consist primarily of a motorized fan. Like all motorized fans, they spin when turned on. A bad inducer motor may contain loose or otherwise damaged parts that vibrate excessively, resulting in loud noises.