Leisure range shows E12 and the cooling fan runs continuously, even when the oven is off.

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

Check the temperature sensor and wiring:

• Locate the oven temperature sensor in the affected cavity and disconnect it.
• Measure its resistance at room temperature. A very low resistance (near 0 Ω) indicates a shorted sensor.
• Inspect the sensor cable for damage where it passes through the oven rear panel; look for melted insulation or contact with metal edges.
• Repair or replace damaged wiring and replace the temperature sensor if readings are out of specification.

Check the control board:

• If the sensor and wiring are good, the main control PCB may be misreading temperature or driving the cooling fan relay permanently.
• Inspect the PCB for signs of overheating or a stuck relay. Replace the PCB if necessary.

Note: A continuously running cooling fan is usually a protective measure; do not bypass safety circuits.