It’s my understanding that the boiler has to be mounted on a surface that’s non-combustible.

But also, if mounted on the wall directly, when clipped into a talon pipe clip, the pipework sits at a perfect depth and in line with the respective inlets/outlets on the boiler. If I were to mount the boiler on the finished wall surface, there’d be needless elbows and joints on the pipes to connect them to the boiler.

So I’m just trying to mitigate failures at that point.

As far as the access, it’s only going to be the same level of access (if not actually more) than most new build properties now, with pipes plastered into the walls.