According to the applicable VDI, SWKI and Ö-Norm guidelines, filling water for heating systems must be pretreated to prevent mineral deposits. Even low levels of hardness can damage modern appliances such as wall-mounted gas boilers, heat pumps and solar systems due to limescale precipitation. With the new PURE H2O demineralisation cartridges from Rothenberger, standard-compliant filling of heating systems in accordance with VDI 2035 is quick and easy. Installers can use the cartridges for new installations and servicing to remove harmful minerals from the filling water. The plug and play system of the PURE H2O cartridges automatically regulates all relevant parameters in order to supply the systems with technical water in accordance with the standards. They therefore offer an easy-to-install system that does not require any additional devices for quality testing.