Display shows E5 and the unit may not defrost correctly or may show erratic temperature swings.

Safety: Unplug the wine cooler before accessing the evaporator area.

• Inspect evaporator: Remove the interior rear panel and check for heavy frost accumulation.
• Test defrost sensor: Disconnect the defrost sensor and measure resistance at a known temperature. Compare to Wolf specs; replace if out of range.
• Check heater continuity: Disconnect heater leads and test with a multimeter. Replace the heater if open.
• Inspect connectors: Ensure all defrost circuit connectors are fully seated and free of corrosion.
• If components test good: The main control board may not be initiating defrost properly and may need replacement.