Power Shower, tingling (current?) in pipes.

[AngelV]

Shower installed by proper plumber.
Shower works, but after it has been turned on for a couple of minutes, the pipes start to get a current in them - not a ZAP but a tingle. After you turn off shower (with on off button on unit) the tingle goes away.
When shower electricity supply is on but shower off, there is no current in pipes, when shower unit switched on the curent in pipes does not immediately appear.
Plumber coming back out to fix, but wondered if anyone else has had this happen and if so what the cause was?

Many thanks!

 

[Taylortwocities]

Is it a new shower, or did it replace an existing one?
Does the plumber have electrical qualifications?
Is the circuit for the shower protected by a safety trip device (RCD)?

 

[AngelV]

Is it a new shower, or did it replace an existing one?
Does the plumber have electrical qualifications?
Is the circuit for the shower protected by a safety trip device (RCD)?

Hi,
Plumber is qualified - he is from a proper company not a local cowboy
It is a brand new power shower and a brand new installation.
The shower has its own ceiling pull switch to allow power to/isolate the appliance. This pull switch is from the lighting ring.
The lighting ring comes from the electrical board which is RCD and has not tripped.

Thanks

 

[pjcomp]

Just to clarify, you say the power comes from the lighting circuit. Do we take it the power shower is a motor only, ie it has hot and cold feed which is then powered out by a motor, it is NOT a cold-only feed which is then fully heated and powered by the shower unit.

PJ

 

[sparkiemike]

Plumber is qualified - he is from a proper company not a local cowboy

This is an electrical fault so get a qualified ELECTRICIAN. Also local does not mean cowboy

 

[electronicsuk]

Presumably the plumber got out his test kit and checked that the ELFI of the circuit he used to feed the shower was of suitably low impedance, and not open circuit due to some previous dimwit breaking the earth connection elsewhere on the circuit?

Also, even if it is pumped only, a lighting circuit is not the ideal place to pick up a supply for a shower.

 

[xr4x4]

Also, even if it is pumped only, a lighting circuit is not the ideal place to pick up a supply for a shower.

ditto...

and it would have to be a pretty bang up to date CU to have the lights protected by a RCD.

 

[AngelV]

Sorry Sparkiemike - no offence meant by 'local cowboy' just a term of phrase.

The power shower is fed by hot and cold water pipes (from HW tank and CW header).

I've done a bit more investigating.

Shower running, pipes do not tingle.
I get in shower (the bath is cast iron) and as soon as I am wet and then touch a metal part (pipe or hose from unit to shower head) there is tingling.

I get out of shower (standing on bath-mat) and water is still running, with a dry hand I can touch the metal parts and there is no tingling.

From this I conclude that I am part of the circuit when I am wet..

I wonder if I were to shower in wellies the problem would go away?

 

[xr4x4]

your brave...you wouldnt get me anywhere near showering with a problem like that.

what type/model of shower is it?

 

[mbga9pgf]

Sorry Sparkiemike - no offence meant by 'local cowboy' just a term of phrase.

The power shower is fed by hot and cold water pipes (from HW tank and CW header).

I've done a bit more investigating.

Shower running, pipes do not tingle.
I get in shower (the bath is cast iron) and as soon as I am wet and then touch a metal part (pipe or hose from unit to shower head) there is tingling.

I get out of shower (standing on bath-mat) and water is still running, with a dry hand I can touch the metal parts and there is no tingling.

From this I conclude that I am part of the circuit when I am wet..

I wonder if I were to shower in wellies the problem would go away?

Do you have any earth connection to your incoming pipework?

Have you got mixed plastic and metal pipeowrk/fittings?

 

[AngelV]

Do you have any earth connection to your incoming pipework?

Have you got mixed plastic and metal pipeowrk/fittings?

No earth on incoming, all pipes metal on new connections.

 

[mbga9pgf]

Do you have any earth connection to your incoming pipework?

Have you got mixed plastic and metal pipeowrk/fittings?

No earth on incoming, all pipes metal on new connections.

I would suggest that you need to get your house water supply pipework earthed if not already so... If you have an RCD on the fault circuit, you will know straight away which area of your circuitry is at fault, as the RCD will trip.

As a temporary measure, if you can find a decent earth, a measurement with a voltmeter (on the AC setting) comparing the voltage of the exposed pipework to the earth will demonstrate if the tingles are caused by your new uber power shower or alternatively a unearthed set of pipework. A warniong now, electrics and water do not mix, I wouldnt be using your shower until this is sorted...

http://www.bbc.co.uk/news/uk-england-london-12198709

 

[sparkiemike]

Any electrician should check that your earthing and bonding arrangements are OK. The wiring regulations are clear that before we carry out additions and alterations bonding and earthing needs to be adequate.

It sounds like yours are not!

An electrician would have also advised you if your bathroom circuits needed RCD protection (a new requirement since 2008).

This work probably needs notifing to building control under part P of the building regs.

Your so called "proper plumber" should have been aware of the above and made arrangements to comply one way or the other.

My advice to you is...

1. DO NOT USE THE SHOWER
2. GET AN ELECTRICIAN IN TO CHECK THIS FOR YOU ASAP.

PS: If you can, switch the shower OFF, there should be a switch near the shower pump (probably in the roof space)

 

[sparkiemike]

some more sober reading

http://www.dailymail.co.uk/news/art...cuted-live-tap-ran-bath-familys-new-home.html

 

[bernardgreen]

DO NOT overlook the possibilty that the shower and pipes are at earth potential and it is the bath that is live.

The foot of the bath close to a damaged cable or junction box under the bath and then the area becoming damp could make the bath itself live.


Use a volt meter between true ground (an earth rod) and the pipe to measure the true potential on the pipes and then measure between true ground and the metal work of the bath.