1 This standard applies to heating boilers with burners using fans up to a no-minal heat output of 300 Kw. They are operated, either with negative pressure (natural draught boiler) or with positive pressure (pressurised boiler) 1n the combustion chamber, 1n accordance with the boiler manufacturers' Instructions.
Particular requirements for boilers which can only be used with open vents are contained 1n a separate document (being prepared).
The requirements of this standard apply to heating boilers which are tested on an authorised test rig.
Boilers 1n accordance with this standard are designed for the heating of central heating Installations 1n wtyich the heat carrier 1s water, and the temperature of which 1s restricted to 100 C at a maximum pressure of 6 bar. For boilers with a built-in or attached water heater (storage or continuous flow heater) this stan-dard only applies to the parts of the water heater which are necessarily subject to the operating conditions of the heating boiler (heating part).
This standard does not apply to gas boilers with atmospheric burners, boilers for solid fuels, oil or gas fired condensation boilers, boilers with oil vapori-sation burners and low temperature boilers. For these boilers there are further requirements.
Note: Low temperature boilers are those operating with a (water) variable temperature up to 40 °C or less, or those which cannot be set at a temperature higher than 55 °C.
2 The purpose of this standard 1s to lay down the necessary terminology, the requirements on the materials and testing of them, and marking requirements.