Defines the constructional and performance requirements and methods of test for indirectly heated, unvented (closed) storage water heaters of up to 2000 l volume suitable for connection to a water supply at a pressure between 0,05 MPa and 1,0 MPa (0,5 bar and 10 bar), and fitted with control and safety devices designed to prevent the temperature of the stored drinking water from reaching 95 degrees C.