prBAS CEN/TS 15502-3-1:2025

Scope of CEN/TS 15502-3-1 EN 15502-2-1:2022, Clause 1 applies with the following modifications: Add after k): l) which are fully premixed appliances equipped with an Adaptive Combustion Control Function (ACCF) that are intended to be connected to gas grids where the quality of the distributed gas is likely to vary to a large extent over the lifetime of the appliance including gas grids for natural gases of the second family where up to 20% hydrogen volume is added to the natural gas (H2NG-Y20). m) which are fully premixed appliances equipped with a Pneumatic Gas Air Ratio controller (PGAR) that are intended to be connected to gas grids for natural gases of the second family where up to 20% hydrogen volume is added to the natural gas (H2NG-Y20), where the quality of the distributed gas without adding the hydrogen is not likely to vary to a large extent over the lifetime of the appliance. Replace ab) and ak) and al) by the following: ab) appliances that are intended to be connected to gas grids where the quality of the distributed gas is likely to vary to a large extent over the lifetime of the appliance (see Annex AB of EN 15502-1:2021), except for fully premixed appliances with a ACCF, as ACCF appliances are designed to adapt to variations in gas quality. ak) appliances that are intended to burn natural gases of the second family where hydrogen is added to the natural gas, except for fully premixed appliances with a ACCF or PGAR (which are covered by this document); al) Partially premixed appliances equipped with an adaptive combustion control function (ACCF).