727cdef5-167f-461e-af07-c7f3ee980577 1 boiler to produce either 20, 25 or 30 kW of heating and domestic hot water production, according to the reference usage scenario defined in the EN 15502 -1 standard and during the 17 year reference lifetime of the product Vaillant Group UK Ltd. 2026-03-26T11:52:50Z 00.00.003