Miele Refrigerator Error Code F115

F115 means the refrigerator evaporator NTC thermistor is reporting a faulty reading. The sensor's resistance corresponds to a temperature below -66°F (-55°C) or above 140°F (60°C), which is outside the valid operating range. This tells the control board that the sensor or its wiring circuit has failed and accurate temperature monitoring is not possible. The refrigerator will need the sensor or associated wiring inspected and repaired.

Continuing to run the refrigerator with an F115 error is not recommended for extended periods. Without a functioning evaporator NTC, the control board cannot accurately regulate the cooling cycle or defrost timing, which can lead to food safety concerns from improper temperatures. It is best to address the fault promptly and transfer perishable food to another refrigerator in the meantime.

Repair costs vary depending on whether the issue is a simple wiring fix or requires a new sensor. The evaporator NTC thermistor part itself typically costs in the range of $20 to $80 depending on the specific model. If a technician is needed for diagnosis and installation, total repair costs including labor generally fall in the range of $100 to $250. Costs may be higher if additional components such as connectors or wiring harnesses need replacement.

A knowledgeable DIYer can inspect the evaporator NTC wiring harness and connector for visible damage, corrosion, or loose terminals without specialized tools. If the wiring looks intact, replacing the evaporator NTC thermistor is the next step and is a relatively straightforward part swap. However, accessing the evaporator area may require removing interior panels, so comfort with appliance disassembly is helpful. If the code persists after sensor replacement, a technician should evaluate the control board.

A power reset may temporarily clear the F115 code from the display, but the fault will return if the underlying sensor or wiring problem has not been corrected. The control board triggers this code based on a live out-of-range resistance reading, so the error will reappear as soon as the unit restarts and polls the sensor. A permanent fix requires repairing or replacing the faulty evaporator NTC thermistor or its wiring.