Display shows E3 and the refrigerator compartment may be too warm or too cold.

Warning: Unplug the refrigerator before removing any interior panels. Sharp metal edges around the evaporator can cause injury.

• Access the evaporator: Empty the refrigerator compartment. Remove shelves and the rear interior panel (usually held by screws and clips). If the panel is frozen in place, defrost the unit first.
• Locate the evaporator sensor: The NTC is typically clipped to the evaporator tubing or embedded in a small holder on the coil.
• Check for ice and placement: If the sensor is buried in ice, fully defrost the evaporator. Ensure the sensor is firmly clipped to the correct location on the coil and not hanging loose.
• Inspect wiring: Follow the sensor wires to where they exit the cabinet. Look for chafing, cuts, or signs of moisture damage.
• Test and replace: Disconnect the sensor and measure resistance. If faulty, replace with a Grundig-compatible evaporator NTC sensor. Clip it securely to the evaporator in the same position as the original.
• Reassemble and test: Refit the rear panel, ensuring no wires are trapped. Restore power and allow the unit to run for several hours to confirm the E3 code clears and cooling is stable.

If the error remains, the main PCB or defrost control circuit may be defective and professional diagnosis is advised.