On 28/01/2021 20:25, Chris Hogg wrote:
On Thu, 28 Jan 2021 17:59:46 +0000, Peter Able wrote:

This house, 30 years old, has two water feeds, one for a drinking water
tap and one that drives through a water softener, in the garage, into
the house indirect system. Twice this year the house has been shaken by
drumming - sounds, and feels, like a helicopter just overhead! I've
managed to stop it by opening the drinking water tap for about 10
seconds. What's causing it and what's the remedy?

TIA

PA

What others have said, plus you can get hammer if the ball-cock in the
CW tank in the loft starts to 'bounce', i.e. vibrate up and down,
causing the valve itself to open and shut rapidly. Once it starts,
it's self perpetuating. Bending the arm of the ball-cock downwards a
little can help, or gluing a flat baffle (piece of plastic or
aluminium sheet) onto the ball on the underside so there's more
resistance to it bouncing. Even closing down your main stop-tap a bit
can sometimes cure it.


Thanks for that. I'm familiar with ballcock valve instability. This
hammering is not feelable anywhere in the house's indirect system -
even at the indirect's main riser. Perhaps I need to investigate how
the supply pipe splits to provide the separate feeds to the water
softener, garden taps and to the drinking water tap. Trouble is that
the wife panics as it really does sound like a helicopter close
overhead, so I have to act drastically. I'll try to track it from the
house to the garage where the supply pipe enters and feeds to garden
taps, the drinking water tap and the water softener / indirect house
system.

PA