The easiest source of power is the lighting ring which passes through the room - I've got the ceiling down right now, so I have easy access to it. Could I legitimately power it from a spur from this circuit? If so would it be right to put a 13 amp FCU in with a 3 amp fuse in it (on the basis that the boiler would be hard-wired into it and no other appliance would be connected to it), or should I do it via a 5 amp round pin socket/plug (which would be unfused - seems less safe to me)?
If the right way to do it is from the ring main (which is doable, just needs a bit more drilling/chasing) then obviously an FCU is the way to go. Is it within the regs to have an FCU reachable from a wash basin in a WC (there's no bath or shower in there)? Or should I hide the FCU within the cupboard - would that be OK?