This European Standard specifies the requirements and test methods for the design, manufacturing, safe operation and the rational energy usage for standard boilers and low temperature boilers (with "boiler" in the sense of "boiler body") from steel and cast iron to be equipped with separately marketed forced draught burners according to the relevant burner standards (for automatic forced draught burners for gaseous fuels see EN 676 and for atomising oil burners see EN 267) up to a nominal heat output of 10 MW. They are operated, either with negative pressure (natural draught boiler) or with positive pressure (pressurised boiler) in the combustion chamber, in accordance with the boiler manufacturer's instructions. This European Standard specifies requirements for boilers with normal operating temperatures between 100 °C and 110 °C and has a "dual structure": For boilers where the shut off temperature of the safety temperature limiter does not exceed 110 °C the Pressure Equipment Directive (PED) requires "Sound Engineering Practice"; For boilers where the shut off temperature of the safety temperature limiter exceeds 110 °C this European Standard specifies the requirements of the PED as stated in Annex ZB. NOTE 1 The "maximum allowable temperature TS" is defined in the PED and its Guidelines. Boilers in accordance with this European Standard are designed for the heating of central heating installations in which the heat carrier is water, and the maximum allowable operating temperature of which is up to 110 °C and the maximum safety temperature limiter of 120 °C. The maximum allowable operating pressure is 10 bar. This standard does not apply to gas boilers with atmospheric burners, boilers for solid fuels, oil or gas fired condensation boilers, boilers with oil vaporisation burners. For these boilers there are further requirements. For gas-fired central heating boilers equipped with a forced draught burner of nominal heat out put not exceeding 1000 kW, see EN 303-7. For shell boilers with a nominal heat output exceeding 10 MW and a maximum safety temperature limiter exceeding 120 °C, see EN 12953 series. NOTE 2 Definitions for standard boiler and low temperature boiler see Council Directive 92/42/EEC.