A draft inducer is an electrically powered blower motor located in the vent system that creates negative pressure to pull combustion gases from the furnace and push them safely outdoors. Also called an induced draft fan, this device removes dependence on natural draft, allowing furnaces to operate in sealed or tight enclosures. Draft inducers are standard on condensing furnaces and high-efficiency equipment, running at 30 to 60 CFM.
Operation and Benefits
The inducer activates when the furnace ignition sequence begins, establishing draft before the main gas valve opens. This controlled venting prevents flue gas spillage into the home and allows use of plastic vent pipe rated for cooler, moist discharge gases. Power venting through sidewalls becomes possible, eliminating the need for vertical chimneys in many retrofit applications.
Maintenance and Troubleshooting
Draft inducers typically last 10 to 15 years before bearing wear increases noise or reduces airflow. Restricted vent lines from ice buildup, lint, or debris cause inducer strain and potential system shutdowns. Regular inspection of vent terminations and cleaning of intake screens prevent 80 percent of draft inducer failures.