Safety: Disconnect mains power before removing the control panel or display housing.

Locate ambient sensor: On many Montpellier upright freezers, the ambient sensor is located behind the top control fascia or near the front grille, sensing room temperature.
Remove control fascia: Carefully unclip or unscrew the display/control panel. Do not pull hard on the wiring.
Inspect sensor and wiring: Identify the small NTC sensor and its two-wire harness. Check for broken insulation, pulled wires, or corrosion at the connector. Reseat the connector firmly.
Test sensor: Use a multimeter to measure resistance at room temperature. Compare to typical NTC values (often 5–20 kΩ at 25°C). If reading is open, shorted, or far out of range, replace the sensor.
Replace sensor: Install a compatible Montpellier ambient NTC sensor. Secure it in its original position so it can sense room air, not cold cabinet air.
Inspect display PCB: If the sensor tests good, check the display/control PCB for burn marks or water ingress. Lightly clean connectors and reseat.

Persistent E3 after sensor replacement usually indicates a faulty display/control PCB, which should be replaced by a qualified technician.

Display shows E3, compressor may run continuously or not at all

Possible Causes