Specification for the installation and maintenance of gas fires, convector heaters, fire/back boilers and decorative fuel effect gas appliances. Independent gas-fired flueless fires, convector heaters and heating stoves of nominal heat input not exceeding 6 kW (2nd and 3rd family gases)|3rd family gases, Maintenance, 2nd family gases, Boilers, Exhaust gases, Flow measurement, Gas-powered devices, Gas-fired heaters, Convection heaters, Fire-tube boilers, Ventilation, Fuel-effect appliances, Gas space heating, Safety measures, Combustion products, Hot-water boilers, Flueless heaters, Installation