When we moved to our current house in '02, there were two boilers in the kitchen; one in a corner and another under the sink.
Both were removed on installation of a new kitchen for a combi. Where the boiler pierced the ceiling looks a mess, as the making good is not as neat as the original, so maybe a less elegant stipple has its merits. It's fascinating though, lying in bed with missus trying to make out, where the man started his efforts.
Well at 80+ I have to find something to do, lying in bed with the missus!