Water hammer

[caveman2]

Since I've had a new copper cylinder and mains water feed to it and the tanks in the loft I have had water hammer. It is caused by the washing machine valves and occurs in the pipework just before the cylinder.
I think it only occurs when the WM is filling with cold but hammers in the pipework some 20 feet away.
Why would it happen at that point could it need securing better at that point. How could I eliminate the air that is causing it and could reducig the water pressure/ flow help. Ideally I would prefer not to take up carpets and floorboards in the bedroom.

 

[gas4you]

First thing I would do and the cheapest and simplest is to replace the ball valve on the cold storage tank in the loft.

 

[caveman2]

When the hammer occurs no water is drawn from the tank only from the mains

 

[JohnD]

...It is caused by the washing machine valves...

not the ball valve, then.

 

[caveman2]

How can I remedy it then please.

 

[JohnD]

Start by clamping any copper pipes that can vibrate (easy and cheap)

(and he's usually reliable but I haven't used it myself)

http://www.lakesidewater.co.uk/products/page36.html