Toilet Cistern Valve won't shut off

diplonics

HI,
I bought the Sevilla Toilet and Sink suite in BWT 4 or 5 months ago and am having a problem with the cistern fill valve. Basically, it won't shut off. The cistern fill value is an anti siphon design very similar to the one at this link http://www.ing-sanitary.com/en/pro_text.php?id=12
I fitted it myself and it seemed to be fine for the first couple of weeks but since then it has been having this problem. I have even replaced it with a brand new identical fill valve that I got off BTW last weekend and still the same problem. I think its probably not set up properly and involves how the membrane, in the above link, is supposed to work. The feed is from a roof tank and not mains so its not under high pressure. The valve seems to fill the cistern fine but when its supposed to stop a very slight trickle still comes out which eventually fills and overflows. When installing there was a second membrane, which I assumed was a spare, however I'm not sure now if it is an extra part that should be fitted for low pressure systems. If anyone has any knowledge of how these fill valves work I would appreciate any helpful tips.

Thanks

builditwell

Hi diplonics

Try the second membrane that you got with the kit. As far as I remember one was high pressure and the other low pressure. Also check for particles of dirt in between the membrane and the screw on valve.

Regards
Builditwell

gsxr1

I acutely fixed two toilets this week with the same problem this week.

I both cases is was the same problem. These systems are very sensitive to dirt and debris in the water.

Try this to see if it works.

turn of the water at the penny valve.

Reach down into the cistern and unclip the fill valve by pulling up the little plastic collar and the whole thing should pull right out.

Once out. Unclip the top the top cover of the fill valve and remove the top exposing the rubber glad.

clean it. there maybe grit black plastic debris from your tank.

put back together and set it .

hope this helps.

Micky Dolenz

gsxr1, is right. Welcome to the world of plumbing. ballcocks, something that should be so simple have become over complex and fragile. When you take it apart besure and remember exactly how it is put together. it may take a bit if playing with but you should get there.

diplonics

Thanks for all this advise. However, I have 2 inlet valves, when I took out the old one (only 4 weeks old), it had lots of little bits of grit and black plastic stuck at various points and filters, which I cleaned out, I replaced the valve with a brand new one though and straight away the problem was the same so I'm not sure if the grit issue is my problem. Probably not helping and something I will keep an eye on.
Re the spare mambrane I have, the new one has the original supplied membrane which is probably for a mains connection which makes me think that its a pressure issue problem, hence the problem is continuing. I took the membrane out off the old valve and cannot see any visual difference between it and the alternative one supplied with the old valve, so don't know if its a spare or low pressure version, but will try swapping around valves anyway tonight and see if it helps.
Alternatively, should I even bother with this anti-sphon set-up or just switch over to a bottom connecting valve and ballcock. Why not stick what has always worked.
Once again thanks for your advice and help.

Diplonics