This British Standard specifies requirements for the selection, installation, inspection and commissioning of gas-fired boilers for central heating and other purposes, which have a total rated heat input not exceeding 70 kW, based on net calorific value. This includes cookers with integral boilers used to provide central heating.
It applies to boilers utilizing 1st, 2nd or 3rd family gases designed to operate in the condensing or non-condensing mode for the heating of domestic or commercial premises by the circulation of heated water in open or closed systems.
This standard does not apply to boilers with a rated input of over 70 kW, nor to groups of boilers with individual ratings of 70 kW or less but with aggregate inputs of over 70 kW as specified in BS 6644. It does not cover the detailed design and installation of the whole heating system, which is specified in BS 5449.
NOTE 1 The installation of boilers with a rated input greater than 70 kW is covered by BS 6644. Additional requirements for the installation of back boiler units are described in BS 5871-1.
This standard applies to boilers which carry a CE mark and also to used boilers which do not carry the CE mark (see 4.2.1).
NOTE 2 In this standard, heat input is expressed in terms of net calorific values (CV), unless stated otherwise. The ratio of gross to net heat input is approximately 1.11: 1 for natural gas, 1.09: 1 for propane, and 1.08: 1 for butane.
NOTE 3 It is essential that persons carrying out the installation of any gas appliance be competent to do so. Annex A gives information about the legal requirements which relate to approved installers of gas appliances.
BS 6798:2000 history
2014BS 6798:2014 Specification for selection, installation, inspection, commissioning, servicing and maintenance of gas-fired boilers of rated input not exceeding 70 kW net
2009BS 6798:2009 Specification for installation and maintenance of gas-fired boilers of rated input not exceeding 70 kW net
2000BS 6798:2000 Specification for installation of gas-fired boilers of rated input not exceeding 70 kW net