Display shows E3 and compressor runs erratically or not at all

Safety: Unplug the wine cooler before removing rear or top panels. Components near the compressor and condenser can be hot.

Steps:

• Locate ambient sensor: On many Transtherm models, the ambient NTC is clipped near the condenser coil or mounted behind the front grille. Look for a small probe with two wires leading to the control board.
• Inspect for heat damage: Check the sensor body and wiring for discoloration, brittle insulation, or melted clips caused by condenser heat.
• Check connections: Follow the harness to the control board and ensure the plug is fully seated and free of corrosion.
• Measure resistance: With the unit unplugged, disconnect the sensor and measure resistance at room temperature. Compare to other NTC sensors in the unit or to expected values. Replace if open/shorted.
• Replace sensor if needed: Install a new Transtherm ambient temperature sensor, securing it in the same location so it accurately senses room temperature but is not in direct contact with hot components.
• Clean condenser: While the rear is open, gently vacuum dust from the condenser coil to improve cooling performance.
• Restore power and test: Reassemble, plug in, and verify that E3 clears and the compressor cycles normally.

Technician tip: If the ambient sensor is good but E3 persists, the control board's sensor input circuit may be faulty and require board replacement.