Water meter bangs!

Wig

I had a WM installed last week and ever since I've heard bangs or thumps in the night, I thought at first it was noisy neighbours, but slowly I came to realise it was coming from the water pipe.

I have today confirmed that the source of the bangs is the water meter. When the flow rate is really minimal, like just a dripping tap or toilet dripping after being flushed...drips for hours but eventually shuts off completely....the water meter creates these bangs in the pipe.

there is a little wheel in the WM which turns as the water flows, and even a dripping tap will cause this wheel to turn slowly. The way I see it the flow rate is not strong enough to turn whatever it is that turns this wheel. But then the dripping tap creates a low pressure on the tap side of the WM when the pressure is low enough the high pressure on the Mains side of the WM pushes the water through the WM and whatever it is in the WM suddenly gives way to the pressure. When it does this there is a little bump or knock noise on the water meter. But inside the house that noise is magnified so it can be a loud thump sound.

Most annoying. I am glad I have found the source of the noise because now I don't have to worry. I will be changing the valve in the toilet soon and the tap doesnot drip when closed properly.

So I reckon I am not going to ask the water company to fix it, because I am going to use it as an early warning system that I have a leak somewhere.

Just thought I'd tell you the story.