Wine cooler beeps and displays E1, interior temperature not cooling correctly or fluctuates wildly.

Safety first: Unplug the wine cooler from the wall outlet before removing any panels or touching internal wiring. Do not work on the unit while it is energized.

Step-by-step checks:

• Power reset: Unplug the cooler for 5–10 minutes, then plug it back in. If E1 clears temporarily and returns, the sensor or wiring is likely faulty.
• Locate the cabinet sensor: Inside most Costway wine coolers, the cabinet NTC sensor is a small probe or bullet-shaped sensor routed through the rear or side wall, often behind an interior plastic cover or near the evaporator.
• Inspect wiring: Remove the rear service panel. Trace the thin sensor wires from the cabinet into the main control board. Look for pinched, cut, or chewed wires, and loose or corroded connectors. Reseat the connector firmly.
• Test the sensor (if you have a multimeter): Disconnect the sensor from the board. Measure resistance at room temperature (around 20–25°C). A typical NTC will read between 5–20 kΩ. If it reads open (OL) or 0 Ω (short), the sensor is bad.
• Replace the sensor: If readings are out of range or the insulation is damaged, replace the cabinet NTC temperature sensor with a compatible Costway part. Route the new sensor along the original path and secure it away from moving parts and sharp edges.
• Check the control board: If a known-good sensor still triggers E1, the main control board temperature input may be defective and require replacement.

When to stop: If you are not comfortable testing resistance or accessing the control board, contact a qualified appliance technician.