How can I stop water constantly running into bowl?

I assume you mean that the ball valve (or modern equivalent) is shutting off the water correctly but you have a dual flush system which is dribbling almost imperceptibly, but continuously, into the bowl.

I wish I knew the infallible answer - and so do many professional plumbers! I've had that problem with 4 different dual-flush units - they seem to be too cheaply designed so that the seal at the bottom of the flush mechanism doesn't close properly.

In my experience, the budget units are a complete waste of money. I had better success with one costing something over £25 but it took a lot of fiddling to get a proper seal and I wasn't really confident it would last.

I may be fooling myself but I think I found that by having a pretty full cistern you stand a better chance of a drip-free seal due to the weight of the water on the top of the ring seal pushing it more tightly closed. Good luck!

A lesson - get that valve seal working properly. I had a new loo installed by bathroom installers in a spare bathroom. Didn't use the loo for a few months then found it unbelievably encrusted with lime inside the bowl - but the rate of water leakage from the flushing valve was impossible to see.

Howdy
August 2013

Most flushing toilet cisterns have an automatic valve arrangement to shut the water off at a certain level - half an inch below the overflow pipe for instance.

Quite often - over time - the adjustment alters (probably because the lock nut has been left loose) - just take the lid off, operate the flush handle and observe the shut-off valve mechanism - how the rising float causes the water inlet valve to close. Pull up on the float and shut the water off yourself.

Adjust the screw inwards towards the valve - be sure to tighten the little nylon lock nut else you'll be adjusting it again next week.

Good luck...

Peccavi
July 2013