F3 is displayed, and the oven will not heat or stops mid-cycle.

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

• Visual inspection: Locate the oven temperature sensor inside the cavity. Check that the probe is intact and not broken off. From the rear of the oven (or top, depending on the model), inspect the sensor wiring for cuts or burn marks.
• Check connections: Ensure the sensor plug is firmly connected to the main wiring harness and to the electronic control board. Reseat the connectors.
• Test continuity: With the sensor disconnected, use a multimeter to check for continuity. An open circuit (infinite resistance) indicates a failed sensor that must be replaced.
• Replace sensor: Remove the mounting screws inside the cavity, gently pull the sensor and wiring through, transfer them to the new sensor, and reinstall. Avoid damaging insulation.
• Control board check: If a new sensor does not clear F3, the control board's sensor input may be defective and require replacement.

Note: Always match the replacement sensor to your specific Ikea oven model; many Ikea ovens share components with Whirlpool/Indesit platforms.