ÖNORM EN 303-3

This European Standard specifies the requirements and test methods for the construction, the safety and the rational energy usage of an assembly made up of a boiler body complying with EN 303-1 1) and a forced draught gas burner complying with EN 676, using combustible gases, hereafter referred to as a "boiler". This European Standard applies to standard boilers and low-temperature boilers with a nominal heat output not exceeding 1000 kW and with a water temperature at normal operation not exceeding 105 °C. This European Standard does not contain all the necessary requirements for: assemblies designed as units ; condensing boilers; boilers intended to be installed in the open ; boilers permanently fitted with more than one flue outlet ; boilers fitted with a draught diverter ; boilers intended to be connected to a common flue having mechanical extraction. This European Standard does not apply to living-space dedicated boilers (see 3.6). If the boiler body has already been tested with a liquid fuel burner, in accordance with EN 303-1, EN 303-2 and EN 304, only the tests described in annex G need to be performed. In the case of a range of boilers, see annex F. This European Standard only covers type testing.