Water Hammer problem

[The Bulwell Brick]

We have had a minor water hammer issue for years but it was never really a problem until the last year or so. It is so loud it sometimes make you jump, it's driving us crackers. It happens sometimes when we use the electric shower or washing machine but then it's not at it's worse. It never happens when we use our taps, flush the loo or use the hose.

It is ten times worse when there is nothing being used in my house but my neighbours seem to be active, we have an adjoining neighbour who is slightly higher up than us and another non adjoining neighbour slightly lower than us.

I fitted an arrester under my kitchen sink on what was the washing machine fill point (this now serves the outside tap and the washing machine is elsewhere). It is fitted about 6 foot from the stopcock. It has made absolutely no difference. Would fitting another on the washing machine point help? Is there anything else I can do?

 

[Scott_D]

Is it a shared water main?

 

[The Bulwell Brick]

The water supply runs down behind the houses, there are no houses behind us. The pipe from our house joins that about 3 foot from the house.

 

[snowhead]

Have you got a combi boiler for Hot water and is the heating system sealed?
Was it originally a conventional system with hot water cylinder and storage tank in the loft?
And is / was there also a small expansion tank in the loft for the heating?
Is there still a water supply into the loft which is now unused?
Or is there a water supply that is still in use or passes through the loft?
Do you have an unvented hot water cylinder?

 

[The Bulwell Brick]

We have a conventional system with hot water tank upstairs, there's a tank in the loft, haven't seen a small expansion tank and there's no unused water supply into the loft. I think it's a sealed system - there's two valves below the boiler to top the system up if the pressure get too low. Don't know if cylinder is vented.
The problem doesn't appear to be anything in my house it happens when we are not using anything including the heating.

 

[The Bulwell Brick]

I spoke to my neighbour today, she is experiencing the same as us ie. pipes banging when nothing in the house is being used.