LED flashes three short and one long blink; inducer does not start; no ignition.

Safety first: Turn off power and gas before servicing.

• Check inducer motor operation: During a call for heat, the inducer should start first. If it does not, verify that the motor is not seized by spinning the fan wheel by hand (with power off).
• Inspect inducer wiring: Ensure the inducer motor wires are firmly connected and not burned.
• Check vent termination: Inspect outside vent for blockage. Clear any obstructions.
• Test pressure switch circuit: With power off, check continuity through the pressure switch and wiring. An open circuit will prevent the inducer from being recognized by the control.
• Professional diagnosis: If the inducer receives power but does not run, or if the IFC relay is not sending power, a technician should replace the inducer or control board as needed.