How to troubleshoot a sub-zero freezer that is not freezing food adequately?

To troubleshoot a Sub-Zero freezer that is not freezing food adequately, follow these steps:
1. Check the temperature settings: Ensure the freezer temperature is set to the recommended level (around 0°F or -18°C).
2. Verify the door seal: Inspect the rubber gasket around the freezer door for any damage or gaps. Replace it if needed to maintain a proper seal.
3. Clean the condenser coils: Dust and debris on the coils can hinder cooling. Clean them using a coil brush or vacuum cleaner.
4. Check the evaporator fan: Test the evaporator fan to ensure it's working correctly, as it circulates cold air inside the freezer.
5. Monitor for changes: Allow time for the freezer to stabilize after adjustments. If the problem persists, contact a professional Sub-Zero technician for further diagnosis and repair.