Both human health and the service life of household plumbing equipment and household heating equipment depend on the quality of water consumed. This brochure is devoted to filtration equipment used in domestic water supply systems, autonomous heating and hot water supply. It describes, in an accessible but highly professional manner, the design, main technical characteristics and scope of application of household filtration equipment depending on its type: wash filters, cartridges, reverse osmosis filters, multi-stage systems. Issues of water disinfection are discussed separately and standards for monitoring its quality are given. The book can be useful to both consumers and specialists, in particular, on issues of installation features and permissible operating conditions of filtration equipment. As examples, the book includes schematic diagrams of water purification in the water supply systems of a cottage, apartment, or summer house.