My room-sealed combi boiler is in the downstairs loo, which I am
currently doing up. I'm planning to build a cupboard around it (in
compliance with the clearance requirements in the installation
manual). At the moment the flex from the boiler goes through a hole in
the wall to a nearby 13 amp socket, workable but not very tidy. I want
to wire it up properly.

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?

Martin Pentreath wrote:
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),

Could do.

or should I do it via a 5 amp round pin socket/plug (which would be
unfused - seems less safe to me)?

Lighting circuits need less stringent disconnection times than socket
circuits - your lighint circuit might not be suitable for having a
socket connected to it (even though the boiler is the only thing likely
ever to be connected).

If the right way to do it is from the ring main (which is doable, just

I think it's a more orthodox way than the lighting circuit. The best way
is a dedicated circuit from the CU, non-RCD protected, so a tripping RCD
doesn't knock off the heating, possibly leading to burst pipes during a
winter holiday.

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

Yes. Obiously it should not be somewhere it can be splashed with water
(or worse!)

(there's no bath or shower in there)? Or should I hide the FCU
within the cupboard - would that be OK?

Yes.

Owain

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.

I'd prefer doing it from the ring main, especially as MCB lighting circuits
are prone to frequent tripping if you have conventional incandescent
lightbulbs.

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?

Either is fine, provided the FCU is not in a position where it would be
subject to direct splashing.

Christian.