1. I gather I need to earth my lovely chrome towel radiator with
an awful green and yellow cable? How on earth (sorry!) do I do
this without having the earth cable dangling up my wall? Would it
be sufficient to bond the (microbore) pipework inside the boxing
(approx 1ft below the towel radiator itself) or does the actual
towel radiator need to have an ugly earth clamp stuck to it?

I've always just bonded the pipework, just below the valve, and have had
this passed as OK in Periodic Inspections.

If it was necessary to bond the radiator itself and not just the pipe,
then surely by extrapolation that would mean it was necessary to attach
clamps directly to all the bath and sink taps as well?!

You can bond to the pipework "in close proximity" to the towel rail
- although a normal earth clamp ain't gonna work on microbore tube

If not, then what should you use instead? I've never seen any special
microbore clamps available?

Cheers for the replies - that puts my mind at rest a bit anyway. I meant
2.5mm^2 in the boxing - not 4mm^2 - d'oh!

Building inspector's coming out to this one so will let you know if it all
goes horribly awry! :-)

Andy