Freezer displays E8 and may not start the compressor; unit stays warm despite power and lights working.

Critical safety: Work on compressor circuits only with the freezer unplugged. High voltage is present. Do not open the sealed refrigeration system.

Diagnostic outline:

• 1. Listen for compressor: When powered, check if the compressor hums briefly then clicks off, or remains silent.
• 2. Access compressor compartment: Remove the rear lower service panel to expose the compressor, start device, and control board area.
• 3. Inspect start device: On non-inverter Bomann freezers, the start relay/PTC is attached to the compressor terminals. Check for burn marks, rattling pieces inside, or melted plastic.
• 4. Test start relay/PTC: Disconnect and measure resistance according to the part specification. Replace if open, shorted, or physically damaged.
• 5. Check wiring and connectors: Ensure all spade connectors are tight on the compressor and inverter (if present). Look for overheated or loose terminals.
• 6. Inverter models: If your Bomann freezer uses an inverter, verify that the inverter module receives proper DC supply from the main board. Inverter diagnosis is complex and often requires a professional.
• 7. Control board evaluation: If the start device and wiring are good but the compressor never receives power, the main control board may be defective.

Warning: If the compressor is shorted or locked, it may repeatedly trip the start device. Compressor replacement requires specialized tools and refrigerant handling certification—contact a technician.