Oven does not heat or overheats; temperature reading on display is clearly wrong

Safety first: Isolate the oven from the mains before any disassembly.

• Locate the temperature sensor: In most Ariston ovens, the cavity temperature sensor (NTC probe) is mounted on the rear wall inside the oven cavity, usually at the top. It looks like a small metal probe held by two screws.
• Visual inspection: Remove the mounting screws and gently pull the sensor forward. Check for burnt insulation, broken wires, or corrosion on the connector.
• Test resistance: Disconnect the sensor plug and measure resistance with a multimeter. At room temperature (20–25°C), many Ariston NTC sensors read around 500–1100 Ω (check service manual for exact spec). Infinite resistance indicates an open sensor; near 0 Ω indicates a short.
• Check harness: Follow the sensor wires to the control board. Ensure the harness is not pinched, cut, or burnt, especially near the rear of the oven.
• Replace sensor if faulty: If readings are out of spec, install a new genuine Ariston cavity temperature sensor. Route the wires away from hot surfaces and secure them with existing clips.
• Reset error: After replacement, restore power and clear the error by switching the oven off at the mains for 1–2 minutes, then reselect a cooking mode and verify stable temperature.