Freezer shows F20; may indicate a general cooling system fault; temperature alarm may be active.

Safety first: Do not attempt to open the sealed refrigeration system yourself. This requires certified equipment and training.

Steps:

• Check ventilation: Ensure at least the minimum clearance specified by Liebherr around the appliance and that vents are not blocked.
• Condenser cleaning: Clean the rear or bottom condenser coils thoroughly to improve heat dissipation.
• Door seals: Inspect gaskets for gaps or damage that could cause warm air ingress.

Remedy: If F20 persists and the freezer cannot reach set temperature despite good ventilation and seals, a sealed system issue is likely. Contact an authorized Liebherr service technician for leak detection, recharging, or compressor replacement.