E12 error, unit may show very low or very high temperature readings that do not match actual conditions

Safety: Unplug the unit before handling sensors or the control board.

Steps:

• 1. Verify actual temperature: Place an accurate thermometer in the middle of the cabinet and compare to the display reading after several hours of stable operation.
• 2. Inspect sensors: Check that cabinet and evaporator sensors are correctly mounted and making good thermal contact (e.g., clipped firmly to liner or evaporator). Loose sensors can read incorrectly.
• 3. Confirm correct parts: If a sensor was recently replaced, verify that the correct AEG part number was used. Using a different resistance curve NTC can cause E12.
• 4. Reset control: Disconnect power for 10 minutes to reset the control. If E12 returns, the board may have a calibration or firmware fault.
• 5. Replace suspect sensor: If one sensor reading is clearly off compared to others (if service mode is available) or compared to the thermometer, replace that sensor with an OEM part.
• 6. Control board replacement: If all sensors are correct and properly installed but E12 persists, the main control board may need replacement.