Air in the system

[Plum Bob 66]

Dear All

Recently attended a customers house after he rang me and explained that after he flushed his toilet the pipework started groaning after about 20 seconds after the toilet filled. I immediatly thought this must be water hammer pertaining to the fill valve shutting off to fast.

On closer inspection this was not the case as the fill valve shut the water off gradually as it was designed to do. Indeed there was the graoning in the pipes lasting for about twenty seconds. Could this possibly be a case of air in the pipework, how would it occur and what could be the cure.

My plumbing suppliers have suggested fitting a mini expansion vessel to the cold feed pipe work.

I would apreciate a bit of advice from all you seasoned vets out there so I can put this one right.

PS. This only occurs when the en suite toilet is flushed??

Best Regards

Plum Bob

 

[Paulplumb]

If it is a traditional ball valve it is probably up the swanney. Had one yesterday in a combination cylinder. Run off a bit of hot water and the whole plumbing system started to shake, bang and sound like a ships horn. Put a new part 2 in and it was good as gold

 

[Toddyplumb]

New washer and new seat £0.10

 

[Plum Bob 66]

Im a bit confused here, the valve is a traditional non torbeck bottom entry float valve that seems in good order and the house isnt particularly old neither, how would this cause such a noise in the system?? Secondly why would running off hot water make the plumbing shake. Not doubting you here just interested to know??

Plumbob

 

[Toddyplumb]

Forget the hot water thing hes talking about another example of the same problem
How do you know its in good order ?

 

[Plum Bob 66]

This is from a visual point of view, but guessing from what you have written there could be a host of problems internally right??

So would changing the valve to a part 2 float valve be a step in the right direction??

 

[Toddyplumb]

Why change the entire valve ? I repeat washer and seat !!
What are they teaching at college !!!!! Bet you could pipe it up in steel though ! Dont take that personally its aimed at the system

 

[Plum Bob 66]

Thanks Toddy plumb

I know exactly were your coming from, yes i could pipe it up in steel ha ha. Im not a time served plumber and this is one big learning curve. Washer and seat it is. What I was realy more interested was how the valve causes this problem, it didnt seem to be typical of water hammer where a quick closing valve causes the shock wave in the system.

Plum Bob

 

[Toddyplumb]

As the washer wears you get high velocity water going through a very small hole or crack . Have a close look at the seat you take out even use a magnifying glass and see what it looks like ! We always change the seat as well as the washer

 

[Plum Bob 66]

Got it now thank you.

 

[WaterTight]

Make sure you come back and tell us if that sorted it or not though..

 

[Plum Bob 66]

Will do !