Miele Washer Error Code F4137

F4137 is a heating system fault specific to the disinfection program on Miele washers. The error identifies a problem with NTC 1, the primary negative temperature coefficient thermistor responsible for monitoring water temperature during the Thermostop step of a disinfection cycle. The Thermostop step is a critical phase where the machine must reach and hold a precise elevated temperature to achieve sanitation, and the NTC sensor continuously reports temperature data to the control board throughout this process.

The fault triggers when the NTC 1 sensor signal falls outside expected parameters during this specific step, indicating either a short circuit or an open circuit condition in the sensor or its wiring circuit. A short circuit causes the sensor to report artificially low resistance values, making the control board read an impossibly high temperature. An open circuit causes the signal to drop out entirely, registering as an extreme low temperature or no signal at all. In either case, the control board cannot confirm that disinfection temperatures are being reached safely and correctly, so it halts the program and throws F4137.

Common contributors to this fault include a failed NTC sensor element, damaged or corroded wiring between the sensor and control board, loose connector pins at either end of the harness, or a faulty heating element that prevents the water from reaching the required temperature range where the sensor would read correctly. Because this fault is program-specific and tied to the disinfection cycle, it may not appear during standard wash cycles, making it important to reproduce the error under disinfection conditions during diagnosis.