We have been having problems with our shower for a couple of days.
There was a noise coming from behind the shower unit.
It was random, and loud.
Like a very loud electric toothbrush.
We took down the metal corner shelf and wee soap dish holder.
nope.
we investigated shower, it was not effected by being switched on or off....
we switched off power supply to shower ....nope.....
This noise seemed to happen after the RAF jet planes flew by.....
When the planes had stopped flying....
When the loo was flushed....
When I run the bath.
When no one was anywhere near it......
It was driving me nuts!
We called out British Gas as they cover our plumbing too.
45 minuets the guy scratched his head,
ran all the taps,
had the shower full on in all its settings.....
Was talking about thinking the shower shouldn't need replacing.
I was getting worried about the cost.....
would the wet wall maybe have to be removed if the shower wasn't the problem.
The bathroom was only painted last year.....
His mobile phone rang and he was chatting away it started buzzing away again,
Then he started roaring laughing!!!
He called me over.....
And said put your hand on the wall.....
So I am standing in the bath with my hand on the wall
he presses the button on the bright pink vibrating razor
that sits on a wee blade holder on the wet wall!

He thinks some water may have gotton into the battery & any vibration like the jets and loo flushing might have been enough to start it vibrating itself......
I have removed the battery!!!
He did our annual gas service while he was here.....and on our paperwork,
he wrote noisy pipes, nil found, situation resolved!!! bless him!