Display shows E5; compressor may not start or may shut down quickly after starting.

Safety first: Unplug the cooler. The compressor terminals carry mains voltage. If you are not experienced with refrigeration electrics, contact a technician.

Steps to address E5:

• Access compressor compartment: Remove the rear lower service panel to expose the compressor, start device, and main PCB.
• Inspect start device: The start relay/PTC and overload are usually housed in a plastic module on the side of the compressor. Check for burn marks, melted plastic, or a burnt smell.
• Check wiring: Ensure all spade connectors are tight on the compressor terminals and there are no signs of arcing.
• Replace start device: If the start relay/PTC is suspect, replace it with a Siemens-compatible compressor start device kit matched to your compressor model.
• Ventilation check: Make sure the rear of the cabinet has adequate clearance and the condenser is not clogged with dust, which can cause overheating and overload trips.

If E5 persists after replacing the start device and ensuring good ventilation, the compressor itself may be failing or the main PCB may be mis-controlling it. These issues require professional diagnosis and often sealed-system work.