toilet making a noise

[JRoberts]

This is the first time I've used this forum, so if this question has already been asked please point me in the right direction and I apologise for the repetition.

My problem is a noisy toilet that is driving me mad as it reverberates through the whole house.

I have one of those loos which has a modern ballcock system (where you flush from the top and has what appears to be a sealed unit inside with a small ball cock and a plastic tube which pumps the water into the cistern - I don't know the model type).

When I flush, the water pumps in but doesn't quite fill up sufficiently enough to push the ballcock up to close off the valve which causes it to try to keep pumping in the water and consequently the rattling/pumping noise. At the moment I'm having to keep taking the top of the cistern off and manually pushing the ballcock down to fill it up enough to shut the valve off. I've also tried adjusting the height of the ballcock to see if this is the problem. In addition the toilet keeps dribbling water into the bowl which in turn is constantly lowering the water level in the cistern - and again causing it to keep pumping.

Do I need a new fitting or is there something simple I can do to sort this out?

Thanks for any help

 

[superdupergasman]

try turning the pressure down using the isolation valve on the mains supply pipe to the cistern.

 

[JRoberts]

Thanks, will give it a go.

 

[TicklyT]

try turning the pressure down using the isolation valve on the mains supply pipe to the cistern.

Partially closing the service valve doesn't reduce the pressure, it reduces the maximum flow rate (and eventually rips the seals out of the service valve, so you can't use it as a service valve).

If the internal overflow is running before the float valve shuts off, the float may be set too high in the cistern, and need adjusting.

A bit of grit in the float valve can stop them closing cleanly.

Some valves tend to snap shut with a 'bang' that can rattle the pipes, especially if the flow restrictor has been left out of the feed pipe.

Some are just noisy from new. Once I went through three different valves that were noisy, then built one that worked quietly by swapping parts between the valves. The design has been modified since that episode.