Toilet cistern overfilling

5 Jun 2006
Reaction score
United Kingdom
My toilet cistern is perpetually overfilling and feeding into the overflow causing a constant drip (at best (flood at worst))...

The toilet is fed from the main tank in the attic via a 15mm pipe which is also linked to washbasin (1st) then the washing machine (3rd).

The system suffers from seriously low pressure (about a 3 inch spurt of water if the pipe is left exposed).

The cistern is filled through a vertical fill valve (fluidmaster 440). I have recently cleaned the valve and replaced the diaphragm with a (red) ultra low pressure one (at the advice of a plumber). This seemed to stop the problem (it slowly stopped happening after a couple of weeks), however, having replaced our washing machine (the fill valve failed), the toilet has started overflowing again. Could this be something to do with the drag of water overloading the valve???

Should I try going back to an old-fashioned ball-cock system?

If anyone has any suggestions then they'd be greatly appreciated - Please help!!!! :(
Sponsored Links
The slow flow and failing valves could all be due to debris in the header cistern and feed pipe. If you get the garden hose up to the wc fill valve input you could try to push bockages back up to the cistern.
Just go back in time to before 1st July 1999, before all this forign plumbing invaded. In the end, the Spitfire pilots died in veign.
Sponsored Links
Would a traditional stop-cock more reliably cut of the feed then?

Any idea why plumbing the washing machine would've started this all up again?

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local