John wrote:
My current boiler is a Worcester Highflow Heatslave which is floor standing.
It is installed in an airing cupboard.

Ever mindful that it was made in 1987, I want to be ready for when it does
need replacing by having some options in mind.

I am concerned that many boilers are wall mounted and I fear that the airing
cupboard compartment is not going to be strong enough to carry a weight. It
is only made of double plasterboard - spaced with off-cuts.

Are there many floor standing boilers to choose from - or could a metal
frame be made to carry the weight of a wall mounted one down to the floor?

The current boiler is rated at 23Kw.

Modern boilers that are floor standing would be much greater power
output or perhaps oil-fired.
Modern combi or system boilers often only weigh about 30kg so should be
ok on a stud wall if the mounting bracket is screwed to the actual wood.