Oven fan runs loudly, with a grinding or rattling noise during operation.

Safety first: Turn off power and allow the oven to cool before accessing the fan.

• Inspect fan blade: Remove the rear inner panel and check the fan blade for bends or contact with the housing. Straighten minor bends carefully or replace the blade.
• Tighten fan nut: Ensure the central nut securing the blade to the motor shaft is tight. Use a suitable spanner while holding the blade.
• Check motor play: Wiggle the fan shaft. Excessive play or grinding indicates worn bearings; replace the fan motor.
• Remove debris: Clear any screws or food debris lodged around the fan.