On Tue, 01 Dec 2009 09:28:26 +0000, Tim Lamb wrote:
I have tried releasing water to see if grit has lodged in the seating
without success.

Hmm, wonder if you can strip it and reassemble and still expect it to work
(i.e. whether the pressure at which it trips is inherent in the design,
or if it's dictated by how tightly some part or other is torqued upon
assembly)

I suspect there's still a particle of something or other stuck in there,
but disassembly might be the only way to get at it.

Alternately, the valve's probably a standard thread - if it'll come off,
it's probably possible to source a 6 bar valve with the right fitting
from *somewhere* even if it's not identical to the current leaking one.

Maybe something like:
http://www.plumbworld.co.uk/pressure...alves-231-0000
.... and maybe you can get fittings to make up an adapter if needed?

This must be an item fitted with all such heaters so somebody must
supply replacements.

Dunno. This side of the Pond they're all pretty standard and you can get
the valves from any DIY store that does plumbing supplies (ditto with
elements, drain valves etc.) - but I don't remember seeing such things in
UK stores (not that I ever had cause to look that hard, though).

cheers

Jules