2012NF D35-500-2-1:2012 Gas-fired heating boilers - Part 2-1 : specific standard for type C appliances and type B2, B3 and B5 appliances of a nominal heat input not exceeding 1000 kW
2000NF D35-345:2000 Gas-fired central heating boilers - Type C boilers of nominal heat input not exceeding 70 kW.