After some advice: Mild tingle from shower when in use

[EFLImpudence]

the risk is one of something becoming inadvertently live, which had not been effectively bonded, and someone making contact between that, and something which is bonded, as seems to be the OP's issue.

Conversely - someone touching a live part and another part unnecessarily earthed rather than left isolated.

 

[FrodoOne]

The client said they got a tingle as they got out of the shower. For sanity check I even got in the shower when done and proved to the client I wasn't getting shocked!
Then I had a message last night saying that it was fine to start with and towards the end of the shower got worse.

Of what material is the Shower Base
and
the Waste Pipe?

If the Waste Pipe is metal it may also require bonding.

 

[FrodoOne]

The client said they got a tingle as they got out of the shower.

The "tingle" was felt where?
Feet?
Hands ?
Both?

What was being touched at the time?

 

[KingDave123]

The shower tray is made of acrylic. Not sure on the waste pipe but I will check on return. Due to the age of the property, I'd be surprised if it wasn't plastic. The tingle was felt in the hands. So, hot and cold copper pipes feeding the shower mixer tap from the shower pump. That's why I bonded them together. Unless there is something damaged cable wise in the vicinity. They haven't had any work done recently. Unless it's something that has slowly degraded. Access is limited so when I am able to get access I will update.
Thanks

 

[FrodoOne]

The tingle was felt in the hands.

Which seems to indicate that the hands (finger tips) were touching different items - at the time.

However, it may be that the other "contact point" was "the feet", where the "tingling" was not noticed - because of the larger contact area and thickness of the soles of the feet (?)

("Tingling" is usually noticed at small area contact points.)

Because of the water involved, I suppose that it is not possible that this could be any form of "Static Electricity" !?!?!