My good old Royel Professional has been annoying me more and more lately. The machine reports "Fill water tank", sometimes even when the tank is still full to the brim or freshly filled. The tank was replaced a few years ago, but then the problem was not yet present.
The error can be temporarily avoided by moving the float back and forth with a magnet at the back of the tank. After removing the external magnet, the machine then usually catches, sometimes for a cup, sometimes longer. I first suspected that there were water bubbles collecting over the float. In the beginning, it was usually enough to put the tank on again with a little pressure. This no longer works.
The problem annoys me more and more. I've already considered just sticking a strong magnet to the back of the machine. But maybe there is a trik how to fix it right? Can the float be demagnetized? Is that available separately? Or can the sensor be relearned? Could a component in the sensor readout circuit have become decrepit, such as an electrolytic capacitor?