Descriptors | Instructions for use, Temperature, Steam condensers, Hot-water boilers, Design, 2nd family gases, Heaters, 1st family gases, Gas space heating, Error correction, Performance testing, Heating equipment, Combustion products, Gas-powered devices, Marking, Central heating, Testing conditions, Hot-water central heating, Classification systems, Domestic, Formulae (mathematics), Rated power, Efficiency, Installation, Condensation, Boilers, 3rd family gases |