Display shows E12; door alarm may sound even when the door is closed, or the unit may not run with door closed.

Safety first: Unplug the appliance before working around the door frame or control panel.

Steps to address E12:

• Check door closure: Ensure the door closes fully and the gasket is not obstructed by shelves or bottles.
• Locate door sensor: On Siemens wine coolers, the door sensor is often a magnetic reed switch in the cabinet frame and a magnet in the door.
• Test magnet alignment: Slowly close the door and observe if the display recognizes the door as closed (alarm stops). If not, the magnet may be misaligned or weak.
• Inspect sensor and wiring: Remove the inner trim near the sensor and check for loose wires or a cracked switch.
• Replace door switch or magnet: If the switch does not change state when a magnet is placed near it, replace the door switch / reed sensor. If the magnet is missing or loose, replace or reattach it.

If E12 persists with a new switch and magnet, the control PCB input may be faulty and require replacement.