wrong shower switch by electrician.

donsbabe

hi there.

Over 2 years ago we had a new bathroom put in and called a local electrician to install the electric shower, a 9.5w one. Over the 2 years the shower itself has got less and less powerful and now randomly goes cold when using it. We thought it was a shower issue, until we noticed the switch outside the bathroom, needed to operate the shower, was boiling hot. Too hot to touch even. then the next day it wouldnt switch on.

This has only happened recently, ive noticed it warm before but never this hot.

turns out that the switch wasnt comptible with the 9.5w shower and it has burned out. Im so glad we didnt have a fire as it was that close to exploding. It obviously, over time, just gave up!

I am angry that the electrician didnt tell/warn us about the switch. Is it his job to do that? or is it mine as the home owner? I had no idea it wasnt able to power the shower. I would have been happy to pay for a new switch for him to install but i had no idea.

But it has been over 2 years ago since he put the shower in..... id like to complain but is it far too late???
thanks.

zax47

In my experience (as an electrician who replaces shower switches on a weekly basis) it's usually the case that a loose connection causes the problems you are seeing. The switches we should fit (wall mounted or ceiling) are rated at 40, 45 or 50A - which is more than suitable for your shower. But, I change at least one a week which has burnt connections, usually on the neutral (it carries just as much current as the live!) 50Hz mains electricity can loosen screws over time, that's why junctions boxes must be accessible for maintenance and inspection, so I'm not in the slightest surprised by this.

You say it's outside the bathroom, so I'm assuming it's wall mounted? Should be a big red lever - not a white one. If, as I suspect, he fitted a regular light switch (rated at only 6A or 10A), or even a 20A isolator, then he's no electrician - he's a cowboy. It's far to late to persue him (IMO), just get a decent one in and have it done properly. You need him to check the cable is suitable to handle a 9.5kW shower too - many times people upgrade an old 7kW one without any thought for the supply cable load and correctly sized cable.

withabix

As above - sounds very much like it was a loose wire termination in the switch.

The switch will have getting hot because the current was being drawn through a small area of copper in the cable due to poor contact and/or loose screw. This produces heat due to the higher resistance of the smaller area of wire.

It wasn't about to 'explode'.

jc808

zax47 wrote: »

50Hz mains electricity can loosen screws over time.

This has come up here before - is this really the case? Sounds like an urban myth

keystone

jc808 wrote: »

This has come up here before - is this really the case? Sounds like an urban myth

No its not actually its a fact and why the wiring regulations were changed so that screw connnection JBs should not be in an inaccessible location.

zax47 wrote:

that's why junctions boxes must be accessible for maintenance and inspection,

Oh and OP you are supposed to tuen the isolator off when not using the shower - not saying you don't - just in case you haven't been.

Cheers

macman

If the OP had been turning the isolator off, then they would have noticed that it was getting hot? I don't think this has happened overnight.

donsbabe

hi, thanks for all the messages. We always turn the switch off and i said before, i had noticed it warm but it went "boiling" all of a sudden. I would have sorted it a lot earlier if i had known about it.

It was a 45A and its one side burned out so i think the first reply has got it spot on. Its being sorted now.
i now know its nothing to do with the origional electrician. so im happier about that now. thanks.

macman

You still need to have the cable checked to see that it is adequate for a 9.5kW shower. If the previous electrician didn't uprate the cable if required, it most certainly is his fault. It needs at least a 10mm cable.
Is the shower on it's own dedicated circuit fitted with an RCD, as it should be?

keystone

macman wrote: »

If the OP had been turning the isolator off, then they would have noticed that it was getting hot?

Just an observation really for general consumption. You'd be surprised (or perhaps you wouldn't) how many people don't.

I don't think this has happened overnight.

Neither do I.

Cheers

donsbabe

yeah it didnt happen overnight..... i didnt realise the switch being warm was an indicator!! sorry, i have no idea about these things. there is a burned out cable . its black rubber with 7 copper (?) thick wires inside it. the black rubber is melted and the copper wires are all charred. Like i said, i know nothing about things like this so im glad i came across this forum for advice from people like you all. thanks again