Christian McArdle wrote in message
. net...

It will, unfortunately. A 2.5mm cable buried in insulation is not
suitable for a 32A ring main.

Agreed -- in fact it's only just OK for the 13A fused spur.

If you can't redo in thicker cable (i.e. the windows have gone in),
I'd run the new section back to the consumer unit and use a 20A MCB.

But that will gain him absolutely nothing. You're replacing a ring which
requires a cable rated at 20A with a radial circuit also requiring a cable
rated at 20A, whilst the cable (as instlled) only has an effective rating of
13.5A.

Alternatively, run it as 2 13A spurs,

That's what I was going to suggest.

with the fan heater off an FCU directly and the sockets off another
fused 13A spur. You can easily do this as you ran as a ring, so
you've already got two supplies to the sockets, provided the FCU
for the heater can be on the first or last socket of the run.

The heater socket or FCU needs to be on a run of its own. In fact with a
single FCU or single 13A socket, it could be an unfused spur.

--
Andy