Hoover oven shows E04 and may cut power to the heating elements; sometimes accompanied by a strong smell of overheating.

Safety first: Turn off the oven at the mains. Wait until all internal parts are cool before working.

• Check external ventilation:
  • Ensure the oven is not tightly sealed into cabinetry without the required ventilation clearances.
  • Clear any dust or debris from front and rear vents.
• Access cooling fan:
  • Remove the oven from the cabinet and take off the top cover.
  • Locate the tangential cooling fan (long, narrow blower above the cavity).
• Test fan operation:
  • Spin the fan blades by hand; they should move freely without grinding.
  • Check the fan motor wiring and connector for heat damage.
  • With caution, briefly power the oven and start a heating function to see if the fan starts after a short delay. If it does not, disconnect power and proceed.
• Electrical tests:
  • Measure resistance of the fan motor; an open circuit indicates a failed motor.
  • If the motor is open or seized, replace the tangential cooling fan assembly.
• If fan is good but not powered:
  • Check continuity from the main PCB to the fan connector.
  • If wiring is intact, the fan driver (relay/triac) on the PCB may be faulty, requiring board repair or replacement by a professional.