Dual flush valve is banging

[Yarn]

Brand new cistern. OK when does a full flush, but for a half flush when the flush valve closes it makes a real bang, which is amplified by the cistern body etc. Tried adjusting flush volume, didnt help.

Any ideas please?

 

[mogget]

A thump is quite normal at the end of the short flush, but not a bang. Could you say more about the quality or tone of the sound?

 

[Yarn]

Well ok then, it is a thump more than a bang. It is quite loud and bordering on unacceptable - with babies asleep next door.

It must be the spring inside as it snaps shut. Its way too violent. You can feel the kick on the unit that houses the cistern.

However, i have taken it out and it does not look like there are any other adjustments to be made.

 

[seco services]

there is no spring.
on a full flush it will fall shut under its own weight
on half flush it will fall shut with half a cistern of water on it.

its gonna bang.

 

[kevplumb]

its gonna bang.

need to stop that or there will be a bathroom full of baby flush valves

 

[Yarn]

I am starting to think that it could be faulty. it is so loud when it shuts off and it vibrates the unit that is housed in. It gives a real kick!

 

[kevplumb]

I am starting to think that it could be faulty. it is so loud when it shuts off and it vibrates the unit that is housed in. It gives a real kick!

its got half a cistern of water on its back

 

[seco services]

just use the full flush then.
half flush ain't worth a rub anyway.