Freezer displays E8 and may show unusually high or low temperature readings not matching actual conditions.

Safety: Disconnect mains power before testing sensors or opening panels.

• 1. Compare display to actual temperature: Place a reliable freezer thermometer inside and compare readings after several hours. Large discrepancies support a sensor or calibration fault.
• 2. Identify all sensors: Siemens freezers typically have a freezer compartment NTC, evaporator NTC, and sometimes an ambient NTC. Locate each and inspect for damage.
• 3. Check for wiring shorts: Look for crushed or pinched sensor cables where they pass through cabinet walls or behind panels. Repair or replace damaged harnesses.
• 4. Verify correct sensor parts: If a sensor was replaced previously, confirm that a Siemens-approved NTC with correct resistance curve was used. Incorrect generic sensors can trigger E8.
• 5. Resistance comparison: At a stable temperature, measure resistance of all NTC sensors and compare. A sensor reading drastically different from the others at the same temperature is likely faulty.
• 6. Replace suspect sensor: Install the correct Siemens sensor and route wiring properly. Avoid tight bends at cabinet pass-throughs.
• 7. Reset and monitor: Restore power and allow the freezer to run for several hours. E8 should clear if all sensors are within expected range.

Warning: If all sensors and wiring are correct but E8 persists, the main control board's measurement circuitry may be defective and should be replaced by a professional.