Furnace will not start; inducer motor does not run; no ignition sequence begins.

Safety first: Turn off power to the furnace at the service switch and breaker. Shut off gas at the furnace gas cock before removing any covers.

Steps:

• Remove the burner compartment door to access the inducer assembly on the flue outlet side of the heat exchanger.
• Visually inspect the inducer motor and blower wheel for signs of overheating, corrosion, or debris jamming the wheel.
• Spin the inducer wheel gently by hand with power OFF. If it is stiff or seized, the inducer motor assembly is likely failed and must be replaced.
• Check the inducer motor wiring harness and plug at the control board for loose or burned connections. Reseat connectors firmly.
• Restore power and call for heat at the thermostat. If the inducer hums but does not start, test for proper voltage at the inducer motor leads with a multimeter (only if you are trained and comfortable working with live voltage).
• If rated voltage is present and the motor does not run, replace the CTC inducer draft motor assembly as a complete unit (motor, housing, and wheel).

When to call a professional: If you are not trained to work with 120/240 V circuits or gas appliances, have a licensed HVAC technician diagnose and replace the inducer assembly.