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What is a draft inducer motor? How does it work? And how do I know if it is going to fail?

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Draft Inducer Motor

furnace draft inducer motor is a part that is relatively new to furnaces; if you have a mid to high efficient furnace, you would have the draft inducer motor. The draft inducer motor was introduced when the government mandated efficiency standards for furnaces.

The purpose of the inducer motor is to move air and gasses out of the furnace and up through the heating vents. This determines how much and how fast air will flow through the heat exchanger.


Although there are different locations where the inducer motor can be located, most them are located near the gas burner compartment of the furnace. The motor is a motor driven wheel assembly or fan, there is an electric box for the power connection and there is a metal sleeve surrounding the assembly. Draft inducer motors can have different sizes of vent pipe diameter, voltage, amperage, wattage, and horse power; it all depends on the size and BTUs of the furnace and your house.


Intra-draft inducer motors are made of different components, durable plastic, metal, or both.

Polypropylene is used to manufacture commercial draft inducer blowers. They are used in corrosive environments because they are better than other material, in corrosive environments.

Fiberglass can also be used, if the inducer motor is going to be used in temperatures above 220°F. Blower sizes are always determined by the size of the unit in which it is located.


When the furnace calls for heat, it starts a sequence of events, which will call the draft inducer motor to purge the heat exchanger of all the gas, that may remain from the previous heating cycle.

This will help make the air cleaner, for when the gas is lit or combustion takes place this will prevent the furnace burners from becoming clogged.

By improving the air quality in the furnace combustion chamber, this will help the furnace become more efficient in its system, thanks to the help of the draft inducer blower.

The operation

When the call for heat occurs, this sends a signal to the furnace to tell the inducer blower motor to turn on, sometimes up to 30 seconds before the furnace burners will actually ignite, but in most cases it will wind up for 30 seconds.

The inducer motor has to run properly and will always have a safety pressure switch connected to the inducer motor's housing.

The pressure switch will monitor the operation of the inducer motor's pressure, to the manufacturer's specifications.

If you ever have problems with your inducer motor, the furnace will generally shut off.

There are many other reasons why inducer motors may not turn on, however most causes are related to a faulty pressure switch, a bad rubber tube, a blockage in the gas vent flues piping, or blower failure.


Unfortunately, most inducer motors are nearly impossible to rebuild, due to the deterioration by the corrosive exhaust. This will result in the purchase of a new assembly. Depending on the type of furnace you have, the price of an inducer motor can range from $100 to $1000.

Thank you for reading this blog.