Wine cooler shows E3 and may not maintain the set temperature; compressor or fans may cycle abnormally.

Safety: Unplug the cooler before inspection. Do not operate with covers removed.

How to troubleshoot:

• Check installation environment: Ensure the cooler is not installed in direct sunlight, near ovens, or in unventilated cabinets. Extreme ambient temperatures can confuse the control, though they usually do not trigger E3 alone.
• Locate the ambient sensor: On many Costway models, the ambient sensor is near the rear grille or air intake, sometimes taped to the back of the cabinet or near the condenser coil.
• Inspect wiring and mounting: Confirm the sensor is firmly attached and not dangling. Look for broken insulation or pulled connectors. Reseat the connector on the control board.
• Test the sensor: With a multimeter, measure resistance at room temperature. Compare to known-good NTC values or to another sensor if identical. Replace if open, shorted, or far out of expected range.
• Replace the ambient sensor: Install a new ambient NTC temperature sensor and secure it in the original location so it accurately senses room temperature.
• Control board check: If E3 persists with a new sensor, the main control board may need replacement.