Display shows E20 and the unit may not cool; compressor may be locked out.

Safety: Sealed system work involves high pressure and refrigerant; only licensed refrigeration technicians should open the system. You may perform basic checks only.

Basic owner checks:

• 1. Listen and feel: When the compressor runs, check if the evaporator gets uniformly cold and if there is any hissing or oil stains indicating a leak.
• 2. Inspect visible tubing: Look for oily residue on joints or coils, which can indicate refrigerant leaks.
• 3. Verify ventilation and fans: Ensure condenser fan runs and coils are clean; poor airflow can mimic some sealed system issues.
• 4. Do not attempt DIY recharge: Gaggenau systems require specific refrigerants and procedures; improper charging can damage the unit and is often illegal without certification.
• 5. Call a professional: If E20 persists and cooling is poor, contact an authorized Gaggenau service technician for leak detection, repair, evacuation, and recharge.

Warning: Do not operate the cooler for extended periods with suspected low refrigerant; it can overheat the compressor.