Replacing an electric shower

[ColJack]

2.5 is rated for a continuous current of around 27A..
cables can take a small orevload for a fair duration, but damage is being done..
your shower is pulling 30A ish, for a fairly short duration so it has time to cool down between uses..

if you put a larger shower on, say 8.5KW, then you're pulling 36A ish, so it's a bigger overload, and the cables will heat up faster and do much more damage to themselves and possibly the material they are run on / in / through, often to the point of causing fire in combustible materials such as floor joists...


As I've already said, it's time to call in a registered sparky and get a proper sized shower circuit installed and a new 10.5KW shower while you're at it..

 

[TheZapster1111]

Thanks. How much will it cost for an electrician to replace the cable? I'm unemployed at present and it seems a mighty big job for such little reward.

 

[ColJack]

unfortunately there's a solid rule we follow..

"can't see it, can't quote it.."

we don't know the distance, the route, ease of access, state of existing CU and wiring etc..

roughly, a days work, plus parts so anywhere in the region of £200-£400 depending..

 

[ban-all-sheds]

And please dont argue with Ban, you wont win

I don't see this as a contest with winners and losers - all I wanted to do was to show that my position was perfectly reasonable.

I found it just too incredible to believe (and still do) that someone could read the Wiki article, and then write "I guess now you're going to tell me there's more to it than that?", no matter how little of it actually made sense to them.

Anybody who can read English can see that it has something to do with cable sizes, and physical dimensions.

 

[TheZapster1111]

And please dont argue with Ban, you wont win

I don't see this as a contest with winners and losers - all I wanted to do was to show that my position was perfectly reasonable.

I found it just too incredible to believe (and still do) that someone could read the Wiki article, and then write "I guess now you're going to tell me there's more to it than that?", no matter how little of it actually made sense to them.

Anybody who can read English can see that it has something to do with cable sizes, and physical dimensions.

What do I have to do to convince you I'm thick? I'm sure you can instantly understand tables showing technical data of an unfamiliar nature, but alas I can not.

Geddit yet?

 

[TheZapster1111]

unfortunately there's a solid rule we follow..

"can't see it, can't quote it.."

we don't know the distance, the route, ease of access, state of existing CU and wiring etc..

roughly, a days work, plus parts so anywhere in the region of £200-£400 depending..

Thanks. In that case, the 8.5kw is going back and I'll try and source another 7.2kw.

 

[ColJack]

no....

you don't seem to grasp that the cable that's installed is too small for the shower that was already on it anyway..

you need to get an electrician out to check the wiring.. might as well bite the bullet and get the job done right..

 

[ban-all-sheds]

you don't seem to grasp that the cable that's installed is too small for the shower that was already on it anyway..

What do I have to do to convince you I'm thick?

 

[333rocky333]

I find it hard to believe everyone rips out old wiring and replaces fuse boxes every time they upgrade their showers.

Unfortunately a lot of people have to, same with large cooking appliances.
Back in the 70's and 80's the showers were not so powerful.
6mm was quite commonly used then.
10mm seems to be the average now but the way things are, 16mm and even 25mm may soon be needed.

With new technology they are getting bigger, someone recently had a 18 kilowatt hand wash unit.

A lot of people not aware, do possibly fit larger units unaware of the damage they are doing to the cables.
This problem will possibly get worse, with the push for more insulation in lofts etc.
But for your own safety you need to confirm that cable and get a shower to suit, or upgrade the cable which may also involve upgrading the fuse box.

 

[bernardgreen]

I find it hard to believe everyone rips out old wiring and replaces fuse boxes every time they upgrade their showers.

TheZapster1111 please take note......If the old wiring is in-adequate and is not replaced then there is a serious risk of fire in your house.

If the shower takes more power than the cable can carry then the cable will become hot. An electric fire element glows red hot because the current in the element wire is enough to make the wire glow red. Copper wire also gets hot when too much current is flowing for the size of the wire in the cable.

 

[RF Lighting]

Have you ever seen what happens to an overloaded cable?

This one is more overloaded than yours, so it happens much quicker, but the theory is the same.

 

[ColJack]

I knew you couldn't resist showing that again....