BS EN 26. Gas-fired instantaneous water heaters for the production of domestic hot water|Specimen preparation, Temperature rise, Automatic control systems, Gases, Performance, Chemical composition, Test equipment, Fire tests, Efficiency, Conversion, Calorific value, Domestic, Test specimens, Gas-powered devices, Hot-water supply systems, Leak tests, Gas valves, Sanitary appliances, Marking, Testing conditions, Endurance testing, Instantaneous water heaters, Designations, Ignition systems (heat engineering), Electrical safety, Safety devices, Adjusting devices, Controllers, Water heaters, Combustion products, Fitness for purpose, Definitions, Heating equipment, Formulae (mathematics), Performance testing, Classification systems, Instructions for use, Fire safety, Heaters