Defines requirements for the installation, including design, inspection, commissioning and maintenance, of gas-fired hot water boilers of net rated heat inputs exceeding 70 kW but not exceeding a net heat input of 1.8 MW.

This British Standard specifies requirements for the installation, including design, inspection, commissioning and maintenance, of gas-fired hot water boilers of net rated heat inputs exceeding 70kW but not exceeding a net heat input of 1.8MW. Groups of boilers with individual net heat inputs of 70kW or less, but with aggregate net heat inputs in excess of 70kW, are also covered. This British Standard is applicable to the installation of boilers that are designed to utilize normally distributed gases of Group H of the second family (e.g. natural gas), and gases of Group P (e.g. propane) and Group B (e.g. butane) of the third family. For the purposes of this installation standard, LPG/air mixtures are regarded as third family gases. This British Standard is applicable to the installation of the following gas-fired hot water boilers: boilers supplied as a complete assembly and conforming to BSEN656 or BS5978 (all parts); boilers supplied as a complete assembly and used in multiple boiler installations where the total net heat input exceeds 70kW and conforming to BSEN297, BSEN483 or BSEN677; boilers and burners delivered separately and assembled on site, comprising: a boiler shell conforming to BSEN303‑1, BSEN12952 (all parts), BSEN12953 (all parts), BS779, BS855 or BS2790; a burner conforming to BSEN676; an assembly conforming to BSEN303‑3 or BS5978‑1 and BS5978‑3. NOTE1 It is recognized that the design, inspection and commissioning require different levels of competence (see 4.1 and 4.2). Where all of these tasks are performed by same person, that person has to have the necessary levels of competence for each task. NOTE2 Although this British Standard does not contain any requirements for industrial processes, the general principles can be applied. NOTE3 The general principles of this British Standard with respect to hot water circuits can be used for boilers exceeding 1.8MW net heat input (2MW gross heat input). For installations exceeding 1.8MW net heat input see IGEM/UP/10 [18]. NOTE4 The ratio of gross to net heat input is approximately 1.11:1 for Group H (natural gas), 1.09:1 for Group P (propane) and 1.08:1 for Group B (butane). It is also applicable to installations that have been converted from burning other fuels to gas-firing. This British Standard is not applicable to: the installation of any heating or hot water supply system associated with the boiler installation; the installation of gas cushion systems (non diaphragm expansion vessels) intended to pressurize the hot water circuit; or installations in hazardous areas, as defined in The Dangerous Substances and Explosive Atmospheres Regulations (DSEAR) 2002 [16], other than those classified as Zone 2 NE, guidance on which is given in IGEM/SR/25 [19] and IGEM/UP/16 [20].