This European Standard specifies the requirements for the installation and commissioning of water-based heating systems in buildings with a maximum operating temperature of 110 oC and a maximum operating pressure of 6 bar. This standard covers the system's requirements for the installation and commissioning of individual components of the system (e.g. heat generators, pumps, controls). It does not cover the specific commissioning requirements for these components. This standard does not cover the installation or commissioning of attached systems (e.g. air conditioning, domestic hot water or ventilation systems). This standard covers only the technical requirements, and does not cover any commercial or contractual arrange-ments between parties.