scope:

This standard defines the classification, constructional and performance requirements, the test methods and the marking of gas-fired central heating boilers which are derived from instantaneous water heaters as defined by standard EN 26. This standard applies to wall-mounted boilers of types B₁ and C₁ which have a single heating body of water equivalent not exceeding 0.082 kg per kW of nominal heat input, have a nominal output not exceeding 30 kW, and are fitted with natural draught burners, without fans, using one or more gases corresponding to the three gas families. This standard concerns only boilers fitted with thermo-electric flame failure devices with permanent pilots. The other flame supervision devices will be dealt with in a later addition to the standard. This standard also applies to the central heating section of boilers which are also designed to provide domestic hot water. Special requirements for modular boilers, intended to be built into a heating battery, will be dealt with in a later addition.