If you have a problem with your water filling tap, then you are in a right adress.
From the Ferroli factory, the make-up valve is mounted in a hydraulic unit, which consists not only of a make-up valve, but also a safety valve, a water pressure switch and Ntc temperature sensors in the models of Ferroli Domina and Domitop boilers. Therefore, there are holes in the tap for feeding Domina and Domitop boilers for mounting immersion temperature sensors. The water systems for Domina and Domicompact boilers are absolutely identical, they differ only in the holes for mounting the temperature sensors.