Oven displays F8 and may not start or may shut down during operation.

Safety first: Disconnect power. Internal metal edges can be sharp; wear cut-resistant gloves.

• Listen for fan operation: When the oven is started (before disconnecting power), note whether you hear the internal cooling fan running. Lack of fan noise suggests a fan or relay issue.
• Inspect vents: Check front and rear ventilation openings for obstructions (foil, insulation, debris). Clear any blockages.
• Access cooling fan: Remove the rear panel or top cover (depending on model) to access the cooling fan assembly. Spin the fan blade by hand; it should turn freely without grinding.
• Test fan motor: With power disconnected, measure resistance across the fan motor terminals. An open circuit indicates a failed motor. Replace the fan motor if open or seized.
• Check over-temp thermostat: Locate the high-limit thermostat on the oven body. Test for continuity at room temperature; it should be closed. Replace if open and not resettable.
• Control board relay: If fan and thermostat test good, the fan relay on the control board may be defective. Replace the electronic oven control board if it is not sending power to the fan.