Dave wrote:

"Peter Ashby" wrote in message
uk...
Feeling frustrated. Last night at 10:05 the toilet siphon broke
unreservedly. So, the wife dropped me at B&Q to pick up a new one this
morning and I walked home. So far so good. Because our cistern sits
directly on the toilet there is no connecting pipe so I have to remove
the cistern to get old siphone off. So I go up into the attic and turn
the gate valve on the pipe emananting from the cold tank, come back down
check sink tap, water gushing, blast. Go up and down fiddling with it,
tracing pipes, reconfirming the system is how I thought. Conclude valve
is bust.

Could the tap you're trying be on the rising main and therfore unaffected by
the tank? You might find the loo is on the rising main too, in which case
shutting off the mains is the best way unless you have a local isolating
valve - see below.

That thought did occur except if the pipe emanating from the header tank
supplies something I haven't found it. Turning the gate valve allows
cold water to flow from: cistern, bathroom sink, bath, kitchen sink
(which includes washing machine/outside tap) which leaves no candidates
(boiler is supplied through a different pipe). Add to this that I had
just filled the bucket from the bath tap before ascending to turn the
tap and I could hear the water entering the header tank. So I am pretty
convinced the gate valve is faulty.

So I go out to the pavement and open the mains valve cover, not only is
the hole full of dirly water but I can't feel anything at full stretch.
Conclude I need a T-bar, blast.

I notice that the pipe to the cistern has what could be a tap or might
be a non return valve, it has a screw so I turn it but it only turns a
1/4 turn and does nothing. Blast again.

That sounds like a local isolating valve - are you sure it doesn't shut off
the water? These things sometimes don't fully shut off if you turn them
through the full 90 degrees - have a fiddle.

Unfortunately it is heavily painted and someone has previously fiddled
and the screw is knackered. I am considering taking the opportunity to
replace it with a tap. The thing is the incoming water enters the
cistern from below which is why I suspect it to be a non-return valve,
in which case I should include one. Are combined non-return and tap
units available? I feel confident enough about taking things out and
replacing but I don't have pipe spreaders or any other plumbing
specific tools (wood is more my thing).

I vaguely remember that under the floor downstairs where the services
come in there is a tap. But that means emptying the small understairs
cupboard. So I decide to leave it till Saturday, we can use a bucke to
flush till then.

So a question, if I turn the water off at the incoming main, will I have
to drain the tank before the water stops?

Could you tie up the ball valve and drain the tank by opening the taps?

I could, being an uninsulated roof in Scotland said tank is heavily
wrapped up and as such I am loathe to interfere unless forced to do so.

Another one, when I have the water off is it worth replacing that gate
valve? I'm assuming that having been fitted it should be fairly
straightforward to drop a new one in?

If it turns out to be faulty, then yes - it'll be relativly easy to replace
it.

I shall endeavour to find one then, thanks.

Peter



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