independently-working without auxiliary power module allows Legionella flushing / circulation, according to ÖNORM B 5019 up to 6 m from each sampling point. Normal operation: bypass closed; Flow runs through mixing valve with a mixed temperature of 55 degrees. Legionella flushing: bypass open; Flow with temperature disinfection of the module at 70 degrees. When flushing has completed, the unit automatically resets to normal operation. All water-carrying parts made of brass alloy. Supplied with white plastic cover.