Freezer displays AL02 and may beep intermittently; temperature reading seems incorrect or unstable.

Safety first: Disconnect power before accessing internal wiring or control boards.

• Power reset: Unplug the freezer for 5 minutes, then plug it back in. Sometimes transient faults clear after a power cycle.
• Locate the NTC sensor: On many De Dietrich freezers, the freezer NTC is behind the internal rear liner or clipped to the evaporator. Remove the internal panel carefully (after defrosting any ice) to access it.
• Visual inspection: Check the sensor body and wiring for cuts, corrosion at connectors, or signs of moisture ingress. Reseat the connector on both the sensor and the main PCB (usually located behind the top or rear service panel).
• Basic resistance check (for skilled users with a multimeter): With the freezer unplugged, disconnect the sensor and measure its resistance at room temperature. Typical NTC values are around 5–20 kΩ at 25°C (exact value depends on model). A reading of 0 Ω (short) or infinite (open) indicates a bad sensor.
• Reassemble and test: If wiring and sensor look intact, reassemble, restore power, and monitor. If AL02 persists, the main control board may not be reading the sensor correctly and should be checked by a technician.