Toilet cistern won't stop filling

[neanderthal man]

Hi all

The toilet cistern won't stop filling and water is flowing out of the pipe to the outside world.

The obvious quick fix is to turn the valve underneath the cistern to stop water going into the cistern but when I turn it anti-clockwise it won't turn a full quarter - it stops after 1/8th (as if it the thread is stopping it). I've sprayed some WD40 on it to see if that loosens it, and I've been trying to turn the screw in both directions to get it moving, but until then I have had to turn the water off to the whole house.

When flushed the water is filling the cistern and the ballcock rises to stop the water coming in (I've checked it and it can't come up any more) but still water keeps coming in.

So I've got two problems:

Why is the water still coming in and what can I do about the valve underneath which I can't seem to turn a full quarter.

Any advice would be much appreciated. I've added a couple of pics to show what type of set up is in the cistern and the valve underneath.

[neanderthal man]

Distaster! I can now turn the screw on the isolation valve in both directions but it keeps going round and round so it won't do its job of cutting off the water.

So whilst I have the water turned on water will be filling the cistern and then going out via the overflow pipe to the outside of the house.

I know I will have to replace everything but has anyone any idea how I can stop the water coming up into the cistern whilst still having water available elsewhere in the house?

[wine~o]

Inlet valve needs replacing, not a difficult job. Water off at the mains empty the cistern, Flush then a sponge to remove any residual water) remove old, replace with new, adjust as necessary. while you are at it replace the iso valve making sure the arrow is pointing the right way.

[neanderthal man]

Inlet valve needs replacing, not a difficult job. Water off at the mains empty the cistern, Flush then a sponge to remove any residual water) remove old, replace with new, adjust as necessary. while you are at it replace the iso valve making sure the arrow is pointing the right way.

Many thanks for the reply.

I guessed it might be the inlet valve that might need replacing and I have manged to replace all the bits and pieces in our two other toilets in the house previously.

The iso valve seems a bit trickier for me as it is attached to the bottom bit of pipe coming up from the floor with a nut. My worry is that if I try and turn that nut (it has been there for 19 years since house was built) I'll end up turning the pipe and mayhem will ensue although that should be mitigated by the fact I'd have turned the water off I guess.

[wine~o]

So long as you have two adjustables shouldn't be an issue. One to clamp the iso valve in place, the other undoing the lower nut. have an old towel handy as there will be a little residual water. (you will only need three hands for that part )

Probably best to replace the Iso valve first.