This document specifies the requirements and test methods concerning, in particular, the construction, safety, fitness for purpose, and rational use of energy, as well as the classification and marking of gas-fired central heating boilers that are fitted with atmospheric burners, fan-assisted atmospheric burners or fully premixed burners, and are hereafter referred to as """"boilers"""".This document applies to boilers of type C, as listed in 4.2:- that use one or more combustible gases of the three gas families at the pressures stated in Tables 14 and 15;- that have a nominal heat input (on the basis of net calorific value) exceeding 70 kW, but not exceedi