Miele Freezer Error Code F165

F165 indicates that the bottom zone evaporator NTC sensor has been detected as defective by the control board. The NTC is a thermistor that monitors temperature at the lower evaporator coil and sends resistance-based readings to the control board. When those readings fall outside expected parameters or the circuit is open or shorted, the board triggers this fault code. The appliance cannot regulate the bottom zone temperature reliably until the sensor is repaired or replaced.

A simple power reset will not permanently clear F165 if the sensor is genuinely defective. The code will return once the control board attempts to read the bottom zone evaporator NTC and detects the same fault condition. The underlying issue, which is a faulty sensor or wiring fault, must be corrected before the error clears reliably.

Repair costs vary depending on whether you use a technician or complete the repair yourself. The NTC sensor part cost is generally in the range of $20 to $80 depending on the specific Miele model. If a technician is involved, labor charges typically bring the total to a range of $100 to $250 or more, depending on your location and service provider. If the wiring harness or control board is also involved, costs will be higher.

A knowledgeable DIYer can replace the bottom zone evaporator NTC sensor, as it typically involves disconnecting the unit, locating the sensor near the evaporator coil, unplugging the connector, and installing the replacement. However, accessing the evaporator area may require removing shelving or interior panels, and working with refrigeration components requires care. If you are not comfortable with appliance disassembly, a qualified technician is recommended.

Operating the freezer with an active F165 code is not recommended. Without accurate temperature data from the bottom zone evaporator NTC, the control board cannot properly manage cooling cycles, which puts food safety at risk. Temperatures in the affected zone may rise to unsafe levels without the appliance signaling a problem. The fault should be addressed promptly.