Hygiene unit for F5S-Therm self-closing thermostatic wall mixers for sanitary and shower facilities, for performing of an automatic hygiene flushing and storage of statistical data. Housing adapter including sensor with control electronics and 6 V lithium battery (CR-P2) as well as solenoid valve cartridge. Activated water hygiene flushing (30 s), fixed interval time 24 hours and saving of statistical data. With option for parameterization and communication via optional, bidirectional remote control.