Water cistern

[PoP]

Must be my week for pipework problems, and I don't think dry bread will solve this one.....

I've been asked to fix a toilet cistern. The plunger into which the bent wire attached to the cistern handle is physically broken, so I'm looking at replacing the syphon assembly. No issue there, looks very straightforward.

Problem is that I can't get the water feed switched off. I turned the house mains supply off and (eventually - it's a big house) drained the system, but it kept coming thru in spurts even after an hour. Seemed to me that this water supply was going to keep throwing water at me for some time to come.

Someone in the past has built a surround around the pipework behind the toilet, under the cistern, and wallpapered without leaving an access hole. Now I suspect there will most probably be a shut off valve under there somewhere, and I'm going back tomorrow with a view to drilling out an access hole so that I can get my hand in. Then hopefully I can shut off the water supply to the cistern and deal with the syphon.

I'm curious as to how one might shut off a water supply which doesn't appear to have a valve in the pipework? Only thing I can think of is to freeze the pipe so as to create an ice bung - is that doable with one of these pipe freezing aerosols I've seen in the sheds? It's always struck me that this was a bit of a gimmick, but maybe it's time for me to give it a try. If the pipe bung works, how long have I got before it thaws out? A couple of minutes?

PoP

[BillP]

You need to shut the supply off and open an outlet below the level of the cistern feed. If the cistern is above the ground floor then open a cold tap on the ground floor. You also need to empty any cold pipework above the cistern. Open all cold taps above the level you are working on long enough to let the water drain out to the open low point tap, you will here air enter as the water drains out. If there is stored hot water, run some off. This will open the float valve in the cold water storage cistern and drain the feed pipe to that. If there are any other toilets above the level at which you are working and they are on the same feed line, then flush them, this drains the feed pipes to them. Your pipes should now be empty above you, and any more water entering will come out of the open tap at the lowest point.

[jerrybuilt]

If you don't need to change the valve, can't you just tie up the float arm and replace the syphon as normal? You might like to unscrew the float to get a bit more room to work in.

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[PoP]

That would be nice, but unfortunately the cistern is one of these that is bolted directly onto the back of the loo - no gap between cistern and loo. So I've got to lift the cistern off to get at the bottom end of the syphon assembly.

I've just bought a can of Arctic Spray. Looks like it might help, but I'm dealing with only a short length of pipe as it comes out of the woodwork behind the loo - most likely not enough room to apply the spray, and there's no other exposed pipework anywhere in the vicinity.

Probably have to cut an access hole in the woodwork behind the loo, where I will hopefully find a cutoff valve. If so then job is done, otherwise I'll be working against time to freeze the pipe and install a cutoff valve before it unfreezes.

PoP

[Dave Liquorice]

And the collar assembly that goes around the pipe that you squirt the contents of the can into I hope.

Doesn't take long to cut a pipe and whack a valve on. Though if you haven't opened taps above and below where you are working I suspect the spurting you reported is due to air trying to get in where the water is trying to get out. Think of gluging bottles etc...

[PoP]

Yep. Just tried it on a spider for good measure. Made a rather neat little trinket for a short time. Not sure the spider thought much of it though.

And I can't see why people want to be frozen after they've passed on. There's no chance they could ever be brought back from where they've gone.

Understood.

PoP

[Rick Dipper]

The pipe freezer work just like they say on the tin, if you follow what it says on the tin exactly.

You could always hold the ball valve up somehow .........

Rick