Vestfrost dual-zone wine cooler shows E3 and one or both zones do not regulate temperature correctly.

Safety first: Unplug the appliance before removing any covers. Avoid pulling on wires directly; use connectors.

Steps to check and fix:

• 1. Identify the upper zone sensor: In dual-zone Vestfrost models, the upper compartment has its own NTC, usually behind a small plastic cover or integrated into the rear liner.
• 2. Visual inspection: Remove the decorative cover if present. Check for condensation damage, broken clips, or frayed wiring. Ensure the sensor head is not hanging loose.
• 3. Check connections at PCB: Access the control board (often behind the top front panel or rear service panel). Locate the connector labeled for the upper zone sensor and reseat it.
• 4. Measure resistance: Disconnect the sensor and measure its resistance at room temperature. Compare to the expected NTC curve. If the reading is far outside range, replace the sensor.
• 5. Replace sensor if faulty: Remove the old sensor from its mounting, pull the cable through the liner carefully, and install a new Vestfrost-compatible upper zone NTC. Seal any penetrations with food-safe silicone to prevent moisture ingress.
• 6. Test operation: Restore power, clear the error by power-cycling if needed, and verify that the upper zone now cools and displays temperature correctly.
• 7. PCB check: If a known-good sensor still triggers E3, the main control PCB may need replacement.