How to Fix / Troubleshooting

Safety: Disconnect the appliance from mains before opening the control housing.

Access control housing: On many Bauknecht freezers, the ambient sensor is located near the display/control panel at the top front. Remove the screws and gently lower the housing.
Identify the ambient NTC: Look for a small probe or capsule with two wires leading to the main board or UI board.
Check connections: Ensure the sensor plug is firmly seated. Clean any visible oxidation with contact cleaner and a soft brush.
Test sensor: Measure resistance at room temperature and compare to expected NTC values. If the reading is out of range, replace the ambient sensor.
Inspect harness: If the sensor is good, check the wiring from the control housing to the main PCB for pinched or broken conductors.
Board diagnosis: If wiring and sensor are OK but F3 remains, the main control board or UI board may be defective. Replacement should be carried out by a professional due to the need for correct part matching and ESD-safe handling.

Freezer shows F3, interior light may work but compressor does not start or runs continuously, temperature unstable

Possible Causes