Toilet flush valve broken -help

Adly812

My flush valve failed to work, meaning water in the cistern continued to fill up and stream into the overfill pipe and then down through into the pan.
I got a plumber in who changed the flush valve. It was working fine and fixed the error for three days. Then I left home and for piece of mind I turned the water off at the mains supply(!!!! stop) . I returned today to find the cistern was FILL and water very slowly trickling into the overfill pipe into the pan!!!! Flush valve not working to stop water rising... I went to the main !!!! stop... It maybe wasn't turned tight enough, as I could tighten it but we're talking a teeny tiny more of a grip turn....
So I turned water back on, flushed the loo And water did not rise and all seemed to function normally...
I'm so confused? Why did the few days away, cause a) water to even get to the toilet with my main !!!! stop off? flush Valve to not work again? C) now it's working???

I've had to leave home again, so I turned off the water again -tightly tight tight shut. Flushed the loo so cistern is empty.l.l
I'm worrying now.. What's the issue ?

Lorian

Do your flush and inlet valves look something like this?

http://www.screwfix.com/p/fluidmaster-bottom-entry-button-cable-dual-flush-bottom-inlet/58353

An you have no large round ballcock floating?

Also please understand it's the INLET valve that controls the water level in the cistern, not the flush.

boliston

If you have a problem with a loo you can normally turn a small valve under the wc tank with a screwdriver to avoid turning off the main stop c**k

southcoastrgi

Are you sure it's on the mains & not fed from a roof tank ?

Adly812

Yup it's the same type of flush and inlet valve similar to your link.. Not a ball !!!!.
I can certainly turn the screw by the toilet, but when I switch the main !!!! stop or waters off at the mains, it stops the water filling the toilet anyway .. So I just turned it off from my mains? ...

Lorian

you may have nothing to worry about then - sometimes that type of inlet valve can slip a little when the mains supply is turned back on.

You might adjust the height a little lower though - in that picture it's adjusted on the black rod on the very far left of the picture, rather than where you would find it on a more typical (old-style ballcock) inlet valve.

lightly pull the rod up and down a little and you'll see how it connects to the black float. only adjust a little! I forget which way to turn, and chances are you'll get it wrong first time, I do :-)

One other thing - don't push/bend that valve stemp at all while adjusting - as the bottom inlet washer can drip if you put too much pressure on it.

Also note that if the inlet valve fails altogether the overflow in the flush valve should be capable of dumping the full inlet flow into the pan, so its unlikely you'll get a flood - by manipulating the float up by hand you can test this and see :-)

Last edit :-) also make sure the float is not fouling on the back of the cistern. I had to play with mine to get a few mm of clearance when fitting it.

Adly812

Thanks very much Lorian. My water supply was off when the inlet valve stopped working whilst I was away, on my return it was not working and water was trickling down into the overflow - pan. I flushed the loo turned on the water When water supply was back on, the cistern filled amd inlet valve continued to work...l
So I'm confused why water was still filling and trickling into the pan when water at the mains was off?