Smeg oven shows Er06 and the fan does not run in convection modes.

Safety first: Isolate the oven from mains power before accessing the rear panel or internal fan.

• Check fan movement: Remove the oven shelves and rear fan cover inside the cavity. Try to spin the convection fan blade by hand. It should rotate freely without grinding. If stiff or jammed, the motor or shaft is likely faulty.
• Inspect for obstructions: Remove any loose screws, foil, or food debris caught in the fan area. Refit the cover and test again.
• Access the motor: Remove the rear outer panel to expose the convection fan motor. Inspect wiring and connectors for heat damage or looseness.
• Test the motor: With a multimeter, measure resistance across the motor terminals. An open circuit indicates a failed motor. If resistance is normal but the motor does not run when powered, the control board output may be defective.
• Replace as needed: Replace the convection fan motor if seized or open-circuit. If the motor is good but Er06 persists and the fan never receives voltage, the main control board's fan driver (relay/triac) likely needs replacement.