Plumbing: Isolating valves - can these fail???

[ItsTony]

Hi,

Just a quick question about the plumbing for the toilet in one of the ensuites of a flat. The flat is a repossesion so all that water had been turned off for a while before being bought.

We've managed to turn the water on in the bathroom to the showers and the sink by turning on the main water and respective isolating valves but the valves for the toilet don't do anything. They just turn round and round loose.

Any ideas before I pay a plumber to come out - thanks?

[Arthur Jackson]

Screwdriver slot isolators only turn 90 degrees from open to shut. If that's what you mean...

[Trevelyan]

If you mean a service ball valve type of isolator with a screwdriver slot rather than a handle then they do just turn round and round. To open it fully you just turn it through 90 degrees and leave it with the screwdriver slot lined up parallel to the pipework.

[Laurel Green]

Possibly tank fed to the toilet? If so, check for another stopcock somewhere, possibly in airing cupboard.

[ItsTony]

It's a valve like this.

http://www.screwfix.com/p/15mm-isolating-valve-pac...

Normally they just turn and you can hear when it's opened up but on this one in particular it just turns round and round very loose. Can they fail or must there be another valve further up that needs opening.

thanks

[Simpo Two]

Quarter of a turn either way. If you don't hear a momentary spurt of water flowing then there's no pressure/demand. Any more valves you haven't found?

[Laurel Green]

That is in the open position. As said, should only need a quarter of a turn from closed to open the valve. Best have a look further along the supply pipe.

ETA: Didn't see your post, Simpo.

[Deva Link]

ItsTony said:

it just turns round and round very loose. Can they fail or must there be another valve further up that needs opening.

thanks

They're usually pretty tight - certainly not freely turning. Wonder if the screw head has become detached from the ball? Usual failure mode is that they start to leak.

[530dTPhil]

Had exactly the same thing happen on the feed to a toilet recently. I wanted to replace the valve in the cistern, turned the service valve in the supply and nothing happened. I ended up draining the cold system down to change the valve before starting on the intended task.
When removed, the slotted part was no longer connected to the part which shut the water off.

[ItsTony]

530dTPhil said:

When removed, the slotted part was no longer connected to the part which shut the water off.

Just to clarify Phil, had the valve failed and didn't let any water through so you drained the pipes as best as you could before changing the faulty valve.

Thanks

[530dTPhil]

Quite the opposite; I couldn't turn off the flow to the cistern. I had to turn the mains off and drain the cold system as best I could to try to minimise the mess when the valve was removed. Unfortunately, the valve was in the downstairs shower room, so probably at the lowest point in the system.

[Ricky_M]

Have you checked that the ball valve in the toilet isn't jammed closed, blocked etc.

Some of the "Ball-o-fix" isolation valves rotate 360 degrees, some only turn 90 degrees.

Very simple to change yourself using an adjustable spanner and water pump pliers (grips).

Turn the main stop tap off, open a cold tap to release the pressure. If its a toilet in a flat, it probably the lowest point, so just bung a couple of old towels on the floor to catch any water when you remove the valve.

[Gingerbread Man]

You are 100% that there is water behind this 'stuck' valve aren't you. It sounds like you're pretty unsure.

Using some grips and a spanner, crack open the joint on the incoming pipe to the isolation valve. As it's a flat, I'm assuming it is a mains cold feed to all. You'll only have to loosen the joint slightly to see if there is water behind it. If yes, try doing the same to the other side. This'll show where the problem is, isolation valve or toilet cistern.

Either way, mains off, open lowest drain off point (quite often a drain off cock above the incoming mains stopcock). Towels down, whip her out and a new one in. Jobs a gooden.

Saying all of this, I'm assuming that you can get to the valve and it's not tiled in or similar.