Any ideas???

[tamz]

Plumb i think the last time i fitted a ballcock to a cws must be 15 years ago. I don't as a general rule do jobbing anymore. I can't be rsed.
It has always been good practice to fit an air cushion at a cws and if i was changing one that never had a cushion i would fit one. I've attached a drawing.

Unfortunately standards in both teaching and the trade itself are falling rapidly to the point where basics are ignored or are not known.

You will never be able to "make it do it" as the pressure differences are so small.

If i remember tomorrow (i'm on the whisky tonight) and i'm not too busy i'll dig out an old 19 canteen book from when i was a boy and scan it and post it up which will explain it better than me.
Btw never fit a flexi to a cws. Total laziness and you are also taking money from your own pocket.
Do things the way they should be done.

 

[tamz]

There has to be air in the system. Depending on the severity of the bang there are several causes. Since you say that there is a pumped shower off of the HW then Id check there is a surrey flange fitted to the boiler! The shower could be Draining the cylinder faster than the cold feed can fill it which introduces air into the system. Irregular expansion of the pipes can cause banging!

Second option! Maybe the customer is wrong about when the banging occurs? It happens. Turn on the HW and heating and see if it bangs! Its possible that the banging is coming from the boiler as air reaches the heat exchanger!

Aye?

Come on now!

 

[solutions]

Aye?

Come on now!

My thoughts exactly..... blind man as trail guide!

 

[ederz]

It's not next door is it?

 

[Mike Jackson]

I put a brand new part 2 ball valve in a CWSC recently and had to go back because it was causing water hammer. Had to fit an equlibrium one to stop it.

 

[kay-jay]

make sure any exposed pipes in loft are clipped properly. as movement can cause vibrations similar to water hammer

 

[plumb_know]

Thanks tamz, yeah I only ever use a flexi to taps when they are hard to get to and always put them in straight, prefer to use copper where I can.

Thanks for all your suggestions I will let you all know how it goes

 

[stratplus]

Plumb i think the last time i fitted a ballcock to a cws must be 15 years ago. I don't as a general rule do jobbing anymore. I can't be rsed.
It has always been good practice to fit an air cushion at a cws and if i was changing one that never had a cushion i would fit one. I've attached a drawing.

Unfortunately standards in both teaching and the trade itself are falling rapidly to the point where basics are ignored or are not known.

You will never be able to "make it do it" as the pressure differences are so small.

If i remember tomorrow (i'm on the whisky tonight) and i'm not too busy i'll dig out an old 19 canteen book from when i was a boy and scan it and post it up which will explain it better than me.
Btw never fit a flexi to a cws. Total laziness and you are also taking money from your own pocket.
Do things the way they should be done.

View attachment 20027

Tamz, what is that air cushion?

 

[Neil K]

Tamz is 100% right. go and fit the air cushion (Tee with a blank on it, I call it a vacuum break) on the cold water main just before it enters the cistern, change the ballvalve for an equilibrium ballvalve whilst you're at it and while you're there make sure there's a surrey flange on the cylinder for that pump doing the ensuite.

 

[plumb_know]

Just an update, found it to be the torbeck float valve, even though I had put a new washer in it it was still making noise. Changed it for fluidmaster pro, now all good. Thanks for all your help

 

[Best]

Thanks for letting everyone know how it went & that you got sorted.
I used to swear by Torbecks as good valves, but stopped using them after they were modified & started to give trouble. Had to replace a Fluidmaster Pro I had fitted little more than a year because it had suddenly started a high pitch drone produced from its stem (caused perhaps by the otherwise perfect looking restrictor). So don't expect them to be silent always.