Hello Jasmina_W.
Thank you for your message. First of all, please check whether the float in the water tray can be moved vertically. It may be that it is stuck due to excessive limescale/contamination. To ensure proper operation, we recommend that you clean and descale the water tray regularly. If this does not help, lift off the top part and clean the contacts with a damp cloth and then dry them properly. You are also welcome to contact us directly (Email: service@stadlerform.com; Tel: +41 41 720 48 48) so that we can take a closer look. We hope that we have been able to help you with our answer and are happy to answer any questions you may have.Your StadlerForm Team

Yes, that's been happening lately. I lift the lid and put it back, that sometimes helps, or jiggle the case a bit. Unplugging it for a few minutes every now and then also helps.