Water leaking into toilet bowl from cistern

justmehere

As the title says, water is continuously flowing into the toilet bowl, causing the attic water tank to be refilling all the time.

The inlet valve in the toilet keeps trickling water into the cistern. Even if I lift the float as high as it can go, it keeps coming. I don't believe the problem is with the outlet (i.e. a worn seal) because the water doesn't flow while the cistern is being filled - only when it reaches the overflow point.
So firstly, does it make sense that the inlet valve could act like this?
Secondly and more annoyingly, assuming I have to change the inlet value, there's no valve/screw to turn the water off into the toilet (cowboys). Additionally the water cock was sealed behind some kitchen cabinets (more cowboys).
I could turn it off from the road (I got new gas heating 2 years ago and that's what the guy did).
However I'm not comfortable doing that - so would be it be enough to tie up the float in the attic water tank and drain it, before removing the inlet valve in the toilet?
Thirdly, I suppose all inlet values are pretty much the same? I will check B&Q and screwfix. If I can't find the exact model, once it fits into the input pipe it should work?
I have emailed a couple of companies but no replies 😔
Would appreciate your opinions!

con747

https://www.boards.ie/discussion/2058421423/water-leaking-into-toilet-bowl-from-cistern

Under the white part should be something like in the link, it's probably failed. https://www.screwfix.ie/p/fluidmaster-multi-pressure-float-valve-diaphragm-washer-30mm/3132d

10-10-20

That's called a bottom-entry fill valve (as opposed to side-entry).

Available in a brass fitting or plastic:

https://www.goodwins.ie/products/viva-universal-fill-valve-4-in-1-brass-2323121.html?filter_set%5B%5D=5160,5167,5194

justmehere

Thanks @con747 and @10-10-20

Would I need to turn the water off if just replacing the diaphragm and not taking the inlet valve itself out?
Something like this guy does (although he switched off the water) at 10:10.
Would emptying the water tank be sufficient? The diaphragm part model is SV90167.

10-10-20

That video is from the UK where plumbing can be somewhat different and we don't plumb toilets directly off the mains supply. Ours come from the cold tank in the attic.

All things being ideal there should be a small isolator valve on the feed pipe from the attic tank, likely to be just behind the bowl. Otherwise isolate it from the attic tank (again there should be an isolator valve on that feed pipe).

justmehere

Hi @10-10-20

Unfortunately there is no valve anywhere around the loo 😒 It's just a pipe from the floor straight into the inlet pipe. Things would have been much simpler if it had been put in right originally. 😢 But anyway.
Yes I think it does come from the attic tank, as that is filling up all the time (it's what alerted me to this problem), which is why I was thinking emptying the tank would let me remove the inlet valve, or just the diaphragm that @con747 mentioned?

I'll have a look around in the attic for that source pipe then and if there's a valve. Don't have high hopes though 🥲

10-10-20

https://www.boards.ie/discussion/comment/123703707#Comment_123703707

If the diaphragm is the right one for the unit then go with that. It can be fiddly and I ended up just replacing the whole units on mine as I wasn't happy with the end result.

As for draining the tank, you might be able to plug the pipe at the outlet within the tank - use a large stopper or bottle-cork - usually works for me.

con747

https://www.boards.ie/discussion/comment/123703707#Comment_123703707

Worst case just open the top of where I said and have something like a small pot to direct the flow back into the cistern so you can check the diaphragm or just take it out and buy a new one to see if it helps. The flow shouldn't be too bad if it's fed from the attic so you could just put the cap back on without the diaphragm until you get back from a supplier with the new one.

justmehere

Hi,

Ok, so I replaced the valve - and now the water is flowing continuously 😥 I put the old one back one, but now that doesn't stop the water either. 😫
A friend said maybe the twist-and-turn cap is worn? This is the white cap that the red handle fits into, in my picture. The idea is maybe air pressure is leaking out. It might explain why even the old seal does nothing now.
The new seal seems to be airtight (I can press it and the little prong comes out, but stays when I keep the handle closed by pressure). Also when I press the seal into the inlet by hand, the water stops. That suggests the seal is ok, but the pressure being applied by the handle isn't enough.

Any ideas?

justmehere

So I just went to B&Q and got a new one! Replacement was straight forward enough.

https://www.diy.ie/departments/fluidmaster-plastic-float-fill-valve/34488_BQ.prd

con747

https://www.boards.ie/discussion/comment/123714795#Comment_123714795

The best easiest solution for a few quid!