Display shows E5 and compressor may not start or may run continuously; temperature control is lost.

Safety: Always unplug the wine cooler before accessing the control board. Capacitors on the board can retain charge; avoid touching bare solder joints.

E5 generally indicates that the main electronic control board in a De Dietrich wine cooler cannot correctly read or process sensor data.

• Confirm sensor integrity: Before condemning the board, verify that all NTC sensors (cabinet, evaporator, ambient) measure within expected ranges and that wiring is intact.
• Inspect the PCB: Remove the top or rear panel to access the main control module. Look for burnt components, swollen capacitors, or signs of moisture damage.
• Check supply voltages: With the unit briefly powered (only if you are trained and using insulated probes), verify that the board receives correct mains input and outputs the proper low-voltage DC to the display and fans. If voltages are missing or unstable, the board is likely defective.
• Reset attempt: Disconnect power for at least 10 minutes to allow the board to fully discharge, then reconnect. If E5 returns immediately, replacement is usually required.
• Replace the control board: Order the exact De Dietrich control module for your model. Label and transfer each connector one by one to the new board to avoid miswiring. Mount the board securely in its housing.
• Final test: Restore power, set the desired temperature, and verify that the compressor and fans cycle correctly and that no error code reappears.