A water heating and treatment system includes a water heater, a hot water outflow line from the water heater, and a cold water supply line to supply water to the water heater. The cold water supply line includes at least one of an anti-scale device, and a UV sanitation lamp. A mixing station supplies a temperature regulated heated water to one or multiple temperature zones. The water heater, the anti-scale device, the UV sanitation lamp, and the mixing station are contained in a single enclosure having at least one transparent wall through which components can be viewed. A method for treating hot water to suppress pathogens and undesired bacterial content in a domestic water system is also described.