Display shows E3, freezer temperature fluctuates, defrost cycles seem irregular (too much ice or frequent defrost).

Safety: Unplug the freezer before removing the inner rear panel or accessing the evaporator area.

• 1. Defrost access area: If there is heavy ice on the rear panel, allow the freezer to defrost (door open, towels in place) until the panel can be removed without force.
• 2. Remove evaporator cover: Unscrew and gently pull off the inner rear panel to expose the evaporator coil. Take care not to damage the aluminum fins.
• 3. Locate the evaporator sensor: Look for a small NTC sensor clipped or strapped to the evaporator tubing, usually wrapped in foil or insulation.
• 4. Inspect sensor and clip: Ensure the sensor is firmly attached to the coil and not hanging loose. Check the cable for cuts or brittle insulation caused by ice expansion.
• 5. Check connection to PCB: Trace the sensor wires to the connector at the control board. Reseat the connector and inspect for corrosion or moisture.
• 6. Test and replace if needed: Measure resistance of the sensor at a known temperature (e.g., after partial defrost when coil is near 0°C). If readings are open, shorted, or unstable when moving the cable, replace the evaporator NTC sensor with a Siemens-compatible part.
• 7. Refit insulation and panel: Ensure any foam or insulation is replaced around the sensor and coil. Reinstall the rear panel and screws.
• 8. Restart and monitor: Restore power and monitor for E3. It may take one full cooling/defrost cycle for the error to clear.

Warning: Do not use sharp tools to remove ice from the evaporator; puncturing the refrigerant circuit will render the freezer non-repairable without professional sealed-system work.