Can anyone work this out.?

Alanp

Last year we had a new toilet fitted and the plumber decided to turn off the water via the stopcock in the street, this turned out to be full of silt/soil so he decided to pull out the washer and turn it off there, toilet fitted ok, and Yorkshire water came out a couple of days later to clean out the street stopcock, not sure when we noticed this but our water pipe started banging, and I mean banging, sometimes even making a similar sound to a cat playing with a spring doorstop. of course we automatically thought the plumber must have done something, but it’s very limited to access behind the kitchen units, ( new fitted kitchen back in 2020) same for the bathroom ( we live in a bungalow and they back onto each other) , the noise was at its worst when the washing machine was in use, as it pulses the water in, I did intend to remove the only access point which would be the bathroom sink unit but I can reach down so far but can feel no pipe work, 
fast forward to March this year and we decided to have a water meter fitted, as I had time off work I thought I’d tackle this after the meter was fitted, Yorkshire water came out to fit the meter and, during the process it sounded as though they were banging the incoming water pipe, which was EXACTLY the same noise we were experiencing, when they had finished, the noise had gone, no noise from either the hot or cold taps, nor the toilet and , the washing machine is now silent when filling, I’ve no idea how the problem was caused or fixed, and, I’m sure the main water pipe is plastic, ( the house was built in the late sixties) I’ve even asked a plumber we use for work and he has no idea, the problem is hopefully fixed now but it’s bugging me as to what it could have been, anyone heard of this before..?

sevenhills

My cold tap used to do similar. Could the work have altered the water pressure and caused the noise to stop?

My tap is now silent, not sure what cured it.

EssexExile

Is the water meter in the house? If so they may have just secured a loose pipe that was moving about. Or it could just be a change in pressure as Sevenhills says. Or a ghost.

Alanp

Water meter outside , as I said , when they were fitting the meter they must have been banging the pipe as the noise was the same, it literally took them 20 minutes to fit the meter, maybe less.

twopenny

Alan, would you send them over to sort out my knocking heating pipes please?

Both my neighbour and I had noisy refil in the en suite only. Both identical. Couldn't solve it.
Then I had a bathroom installed (nothing useful there before) and presumably he had to turn the water off.
He opened the mains tap more than before and voila! No more noise.

I still know when my neighbour is going to bed though because she won't try it 

Alanp

Someone suggested it might be an airlock, but not too sure about this theory, it was the cold water supply to the house…

Murmansk

I guess it's what you might call water hammer. Perhaps changing the amount by which the stop tap is opened a bit might sort it should it arise again.

Alanp

Murmansk said:

I guess it's what you might call water hammer. Perhaps changing the amount by which the stop tap is opened a bit might sort it should it arise again.

I did lower the pressure via the stop in the house but it made little difference