Oven display shows E04 and the oven does not start or stops mid-cycle.

Safety first: Isolate the oven from mains power before removing any panels.

• Access the cooling fan: On Candy built-in ovens, the tangential cooling fan is usually mounted at the top rear, behind the top cover. Remove the oven from the cabinet if required and take off the top panel.
• Inspect the fan: Check that the fan blades spin freely by hand. Remove any debris or insulation obstructing the fan. If the fan is seized or very stiff, the motor is likely faulty and should be replaced.
• Check wiring: Inspect the fan connectors and wiring harness for heat damage or loose connections. Reseat connectors firmly.
• Test the fan motor: With a multimeter, measure resistance across the fan motor terminals. An open circuit indicates a failed motor. If you are competent and local regulations allow, you can briefly power the fan motor directly (using an appropriate test lead and full safety precautions) to confirm operation.
• Control board output: If the fan motor is good, the fault may be on the main control board (triac/relay not switching). This typically requires board repair or replacement by a professional.