Shower cable size

[amfisted]

Almost unbelievable, I know, but the old shower continues to work and I still haven't done the job. The shower I bought to replace it in 2017 is now out of warranty by about four months.

Having decided that the 4mm cable needs to be changed on the assumption that I've just been lucky that the circuit has never blown ( its an 8.5kw shower), I had a quote from an electrician to do the lot: renew circuit in 10mm cable, supply and fit 50amp MCB, 50amp isolator and a basic 9.5kw shower plus labour for the shower swap, totalling just under 400 quid plus VAT. Not only does it seem a lot to me, but he seems to have disappeared off the face of the Earth since giving me the quote (perhaps he quoted high because he didn't want the job).

I'm now wondering whether to renew the circuit in 10mm myself, connect up the new isolator and the new shower, then (if I can get hold of someone who will do such a minor job) get a spark to come along, connect to the CU and test.

I'd say wish me luck, but I'll probably still be babbling on about it this time next year.

 

[John D v2.0]

You could have started a new thread rather than bumping a 6 pager from spring!

10mm will be plenty for any shower, connecting isolators and showers isn't rocket science, and I'm sure someone would do a small job, the hard part might be taking responsibility for your partially completed circuit. You could just do the pulling in the cable part perhaps, might be more likely to get someone to do it.

 

[winston1]

6mm cable would be more than adequate and a lot easier to work with.

 

[JohnW2]

You could have started a new thread rather than bumping a 6 pager from spring!

WEll, it was his thread (started nearly two years ago), and what he has now added is, at least in some senses, an update to the original discussion - so I'm not sure that I would necessarily describe that as 'bumping a thread' - certainly not as bad a case of 'bumping' as we often see!!

Kind Regards, John

 

[Simon35]

Almost unbelievable, I know, but the old shower continues to work and I still haven't done the job. The shower I bought to replace it in 2017 is now out of warranty by about four months.

Having decided that the 4mm cable needs to be changed on the assumption that I've just been lucky that the circuit has never blown ( its an 8.5kw shower), I had a quote from an electrician to do the lot: renew circuit in 10mm cable, supply and fit 50amp MCB, 50amp isolator and a basic 9.5kw shower plus labour for the shower swap, totalling just under 400 quid plus VAT. Not only does it seem a lot to me, but he seems to have disappeared off the face of the Earth since giving me the quote (perhaps he quoted high because he didn't want the job).

I'm now wondering whether to renew the circuit in 10mm myself, connect up the new isolator and the new shower, then (if I can get hold of someone who will do such a minor job) get a spark to come along, connect to the CU and test.

I'd say wish me luck, but I'll probably still be babbling on about it this time next year.

Doesn't sound particularly expensive to me. Supply all materials, install and test, business overheads etc.

 

[amfisted]

Well, having considered the alternative options I accepted the quote via email about two weeks ago, but I've heard nothing since. Which is why I'm now considering, once again, doing most of the work myself.

I did think that despite the passing of time since the original discussion, adding to the thread would make more sense insofar as it would save anyone digging around the forum trying to find the original thread lest they needed any other information in order to contribute.

I'm well capable of connecting cables to the isolator and shower, lifting loft boards and laying 10mm along the line of the original supply cable, although the route of circuit cables from the loft to the CU is currently a mystery to me, disappearing as they do down a hole in the loft then reappearing under a wooden panel in the concrete floor of the porch next to the CU. Presumably they must have been routed behind an architrave or within trunking somewhere as yet undiscovered. We had the earth bond renewed in 2014 (I was away whilst the spark was here) and when I got home, plastic trunking had appeared inside one of the fitted wardrobes in the front room which is closest to the CU. However, it doesn't look substantial enough to take all the cables that enter and exit the loft, so I presume it carries earth only. I'll open it and have a look.

Surely the "taking responsibility for your partially completed circuit" bit would be covered by having a spark test the circuit?

 

[Simon35]

Well, having considered the alternative options I accepted the quote via email about two weeks ago, but I've heard nothing since. Which is why I'm now considering, once again, doing most of the work myself.

I did think that despite the passing of time since the original discussion, adding to the thread would make more sense insofar as it would save anyone digging around the forum trying to find the original thread lest they needed any other information in order to contribute.

I'm well capable of connecting cables to the isolator and shower, lifting loft boards and laying 10mm along the line of the original supply cable, although the route of circuit cables from the loft to the CU is currently a mystery to me, disappearing as they do down a hole in the loft then reappearing under a wooden panel in the concrete floor of the porch next to the CU. Presumably they must have been routed behind an architrave or within trunking somewhere as yet undiscovered. We had the earth bond renewed in 2014 (I was away whilst the spark was here) and when I got home, plastic trunking had appeared inside one of the fitted wardrobes in the front room which is closest to the CU. However, it doesn't look substantial enough to take all the cables that enter and exit the loft, so I presume it carries earth only. I'll open it and have a look.

Surely the "taking responsibility for your partially completed circuit" bit would be covered by having a spark test the circuit?

Sounds even less expensive now, lifting and replacing loft boards, cabling on an unknown route. Getting your money's worth there for 400 quid. All a bit moot of course, if your electrician has vanished.

 

[winston1]

Why are you still wanting to use 10mm? 6mm is more than adequate. Whole houses are often supplied by 10mm.

 

[John D v2.0]

I did think that despite the passing of time since the original discussion, adding to the thread would make more sense insofar as it would save anyone digging around the forum trying to find the original thread lest they needed any other information in order to contribute.

you can just copy and paste the link from the URL bar from the old thread into the new one. But it's not a massive deal, it was just a suggestion!

Surely the "taking responsibility for your partially completed circuit" bit would be covered by having a spark test the circuit?

Not exactly, testing couldn't detect every problem e.g. wiring not buried deep enough in the wall, or insulation damaged. It'd probably not prevent a spark from being interested, but the more work you do, the more risk for them, so it could tip things over the edge. Obviously having to run the cable themselves is also a risk so that part would surely help! Hope that helps, John

 

[JohnW2]

Since this thread has now been split from the (fairly ancient) original to which it is partially a follow-up (so, thread-splitting can be done in this forum! ), in case anyone wonders what on earth it follows on from, the original thread can be found here .

Kind Regards, John

 

[amfisted]

Sounds even less expensive now, lifting and replacing loft boards, cabling on an unknown route. Getting your money's worth there for 400 quid. All a bit moot of course, if your electrician has vanished.

Its actually 400 plus VAT, so nearer £500. However, I had an email from him today and we'll be arranging the work for early next year. Meaning that instead of crawling through lofts trailing cables I'll be making tea, something I'm much better at since my knees and back turned to dust.

 

[amfisted]

you can just copy and paste the link from the URL bar from the old thread into the new one. But it's not a massive deal, it was just a suggestion!

Not exactly, testing couldn't detect every problem e.g. wiring not buried deep enough in the wall, or insulation damaged. It'd probably not prevent a spark from being interested, but the more work you do, the more risk for them, so it could tip things over the edge. Obviously having to run the cable themselves is also a risk so that part would surely help! Hope that helps, John

Probably hypothetical now that the spark has been in touch, but thanks anyhow for the response and advice.

 

[amfisted]

Why are you still wanting to use 10mm? 6mm is more than adequate. Whole houses are often supplied by 10mm.

I'm pretty sure I've read here and elsewhere that its a good idea to go for larger cables so that the installation is working well within its capacity, and in case at some point in the future the homeowner wants to upgrade.

 

[Risteard]

Whole houses are often supplied by 10mm.

It's pretty unusual for them to be supplied by cable with a cross-sectional area of less than 16mm^2, actually.

 

[EFLImpudence]

Many flats are fed by 10mm². It is, after all, adequate for 60A supplies.

It's probably why people fit 25mm² tails regardless.