On Mar 19, 12:46*am, wrote:
You're thinking of "Water Fuses" (trademark), seehttp://www.waterfuseltd.com/how.htm
but I'm not sure that will do quite what the OP wants.

£195 - Australia derived.

Thames Water were pushing water fuses a few years back, but
nanny said it wasn't safe for you to fit them yourself. It wasn't
clear whether they'd sell you one regardless.

Amusingly they say "should" be fitted by a CORGI-approved plumber, I
say amusing because "should" is not the same as "must" at least from a
legal perspective. Australia loves its approved tradesman system, well
except those who moved to new zealand away from nanny because they
aren't allowed to wipe their backside without a trail of brown
overalls.

There are many other similar products on the market, an issue I have
with all is the risk of the valve & pre-valve pipework freezing. Many
people have lead incomers installed tight against solid double brick
walls, hard to insulate, easy to freeze.

Responsibility for the water main should really extend to the stoptap
indoors, for obvious reasons utilities would like to avoid this -
along with avoiding any competition from ability to switch supplier as
with Gas & Electricity.