I‘ve experienced the same problem and called to the service rep. here in Sweden and they came and had a look at it and replaced the sensor for the thermostat on extended warranty due to the fact that Miele have had a lot of problem with these.’
The way to determine if it is likely to be the sensor is if the entire cooling panel at the back of the fridge is cold/frozen then it’s the sensor, but if it’s only the top part it’s most likely not enough cooling fluid in the system ie. a costly exorcize.
Eskil, December 2010