Refrigerator compartment warm, freezer temperature acceptable, frost buildup on rear panel of freezer.

Safety: Disconnect power before removing interior panels. Heater and metal edges can be hot or sharp.

Steps:

• 1. Inspect for frost: Look at the rear interior panel of the freezer. A thick, even layer of frost indicates defrost failure.
• 2. Manual defrost: Turn off the appliance and leave doors open for 24 hours to melt ice. Protect floors from water. This is a temporary fix.
• 3. Access evaporator: Remove the rear freezer panel to expose the evaporator, heater, and defrost thermostat.
• 4. Test heater and thermostat: With power off, check continuity of the defrost heater and thermostat. Replace any open components with Gaggenau-compatible parts.
• 5. Clear drain: Ensure the defrost drain below the evaporator is not blocked with ice or debris. Flush with warm water until it flows freely.
• 6. Control board: If all defrost components are good but the unit never enters defrost, the main control board may be faulty and should be replaced by a technician.