In order to fit a new condensing boiler in my mothers kitchen, the most convenient position would be to brick up the smaller of 2 windows on the same wall (used to be the window in a long gone pantry) & fit the boiler there. However as we are anticipating a long wait for the guy to visit & advise I to want brick up the opening in preparation, but if the distance between the new flue & the window will not meet the regs.,then we will have to have a re-think about the boiler position I read in an old post that the distance between the flue & an opening is a min of 300mm. Is this still the case. Many thanks