Refrigerator display shows E0 and cooling performance is reduced or intermittent.

Safety first: Unplug the Grundig refrigerator from the mains before removing any panels or touching wiring. Do not work on live circuits.

• Power reset: Disconnect power for 5–10 minutes, then reconnect. Sometimes the control board will clear a transient sensor reading error.
• Check sensor location: Open the fresh food compartment and locate the small plastic cover or housing where the temperature sensor (NTC) is mounted (usually on the rear wall or ceiling). Make sure it is not encased in ice or blocked by food items.
• Inspect for ice buildup: If the sensor area is iced over, defrost the unit by unplugging it and leaving doors open for several hours. After defrosting, restore power and see if E0 clears.
• Check wiring and connector: Remove the interior sensor cover (usually clipped or held by 1–2 screws). Gently pull out the sensor and inspect the wiring harness leading to the cabinet. Look for cuts, pinches, or corrosion. If accessible at the main control board (often behind the rear lower service panel), verify the sensor plug is firmly seated.
• Test the sensor (for advanced users): With the fridge unplugged, disconnect the sensor from the main PCB and measure its resistance with a multimeter. Compare to a typical NTC curve (e.g., ~5–10 kΩ at room temperature). If it is open, shorted, or far out of range, replace the sensor.
• Replace the sensor: If defective, install a compatible Grundig refrigerator compartment NTC sensor, route the wiring as original, and secure the sensor in its holder. Reassemble covers and restore power.

If E0 persists after sensor replacement and wiring checks, the main control board may be faulty and should be diagnosed by a qualified technician.