Electric Shower - ideal location for switch?

[nonymouse]

Any ideas? Unlike most houses, getting the cable from the fuse box to the bathroom is easy in our house. However, getting the cable to a switch in the ceiling and then back to the shower is much more problematic. I can get the switch easily into the cupboard with the storage tank and wondered if this was a good idea.

Not being a plumber or electrician I would really appreciate any thoughts on this topic. Also, is electric really the way to go? I'm assuming their cheaper to run; we currently have a gravity fed system but our cold water supply from the mains is good.

Thanks in anticipation of some expert advice - Bear

[Sparks]

You assume incorrectly if you have a gas boiler :-) heating with electricity is far more expencive then gas.

If it were me, I would go for a power shower (rather then an electric shower) You would need to run a hot pipe from your hot water tank, and also a cold water pipe from your cold water tank. You will also need a low current electrical feed (Personally I would always RCD protect this, although I am not sure it is against the regs to not do so)

This type of shower pumps the water from the hot and cold feeds (so you must NOT connect it directly to the mains water supply) they produce a much higher flow rate then electric showers.

Sparks...

[nonymouse]

Thanks Sparks...

Do I assume correctly that most gravity fed showers can be pumped then?

Our current shower has something called a Venturi valve - apparently a way of boosting the flow without the need for electricity. As we're having the bathroom napalmed we thought it wise to update the shower - but nothing is simple! Our shower ideally needs to have the pipes exposed - and using a power shower would require two pipes running down the wall as oppose to one (with an electric system).

Using a pump presumably does not draw too much electricity then? I know electric showers are typically 8.5 - 10.5 Kw meaning a current draw of around 40 amps. I have no idea how much current pumps draw (although I'm assuming it's obviously related to their Kwattage)

[Owain]

The switch must be within sight of the shower or of the type that is lockable-off for maintenance.

Electric several times the cost of gas, and also very limited in output.

If you have an existing hot water system in good order then consider a pumped shower.

Owain

[Sparks]

I can't see why not, even if your shower does not have a pump, and was never designed to have one, adding a pump is very easy - to the shower, it's just like having more height between it and the tank. Adding somthin like this is fairly straight foward

Our current shower has something called a Venturi valve - apparently a

Can't you chase them in the wall if you are nuking the room anyway!?

We are talking hundreds of watts rather than thousands, so probably around

500-600 watts (2.5A)

When I do our bathroom (Gravity fed hot and cold water, like you), I will probably have a thermostatic valve in the bathroom, and stick a shower pump up in the loft, because:- I don't like the idea of having a box with mains electricity in front of me when I am naked and wet! I don't like the look of a big box screwed on the wall when I don't have to have one, If the pump breaks, I expect it would be easier to replace, as it doesn't matter if it looks different/is a different size etc.

Sparks...

[Sparks]

A friend of mine has an electric shower, but the isolator is a switch outside the room above the light switch for the bathroom - as this switch can't "see" the shower (It is on the other side of the wall to the shower unit), should this be a lockable one then? Has there always been this requirement, as this was installed, maybe, 10 years ago.

Do you know where one could be obtained - Screfix and TLC don't seem to do one!

Ta, and, to the OP, sorry for hijacking the thread!

Sparks...

[chris French]

In message , Sparks writes

Pass.

you can Fan Isolator 3 pole switches which are lockable. Or FCU's normally seem to have fuse holders with a hole for a padlock to lock them

[nonymouse]

.=2E. returning to the electric versus pumped argument...I read a lot on the Internet that suggests electric is cheaper than other types of shower as you only heat the hot water that you are going to use.

I'm also a little concerned as during the winter we have to turn the thermostat on our storage tank up to 70=B0C to get decent hot water for our shower - and even then I wouldn't say it's as hot as we would like.

Does a pumped shower require a separate isolater switch similar to an electric one then ...

[David Hansen]

On 28 May 2006 23:57:46 -0700 someone who may be "nonymouse" wrote this:-

As with most interesting things there is no simple answer. Electric showers have relatively low flows. A gravity shower of similarly low flow will use relatively little water and that would be heated anyway. If the hot water cylinder is well insulated then the electric shower is probably about the same running cost in winter, as the water would be heated anyway. In summer the electric shower may cost a little less, though this depends on how much water is being heated anyway.

High flow showers can almost empty a typical hot water cylinder. Heating this water by a gas boiler and heat exchanger will cost about half of the price to heat it by day rate electricity.

If the water is heated by sunshine then the running cost of a high flow shower is almost nothing, unless two people want a shower in rapid succession.

Where is the thermostat on the cylinder? What sort of system do you have?

Yes and no. Such things are generally best fed from the ring main via a switched fused connection unit. The wiring and switch are rated at rather less than half those for an electric shower.

[nonymouse]

As far as I understand, we have a gas boiler and a gravity fed shower system with a hot water storage tank upstairs. There is a cold water header tank in the loft, and a separate one that supplies the radiators.

Sorry for being a little thick here but I don't see how an electric shower is cheaper in the Summer...surely it takes less energy (gas) to heat the water during the summer...is this not cheaper than turning on an electric shower (pulling potentially 45amps!) ... although granted the shower would probably only be on for about 10 mins :-)

Oh, if I install a power shower I'm guessing there's no need to wire up to the mixer in that the pump etc. are all isolated and presumably the pump automatically fires up when the mixer is activated???

[Owain]

It should be, so that there is no risk of someone switching on when someone else is working on the shower.

16th Ed regulations were in force 10 years ago, so yes.

Hmmmmmmm.

Owain

[Owain]

Neither of which will be suitable for an electric shower at 30-45A though, before anyone gets any ideas ...

Owain

[Owain]

Electric shower *might* use less energy because its output is so limited, it heats less water and is so miserable you woudln't want to spend much time under the spray.

However, as electricity is 2-3 or more times more expensive than gas, the electricity can end up costing more.

Pumped showers can use *lots* of hot water if you run them at a high setting with one of those watering-can deluge heads.

Yes. And the pump doesn't have to be in the bathroom.

If both your hot and cold bath taps are fed from the tank (not cold direct from the main) then you can put the pump on the pipes to the bath and enjoy faster bath-filling. May also be a lot less plumbing work than getting mains cold to the bathroom (as would be required for an electric instant shower).

Owain

[crb]

It should be, so that there is no risk of someone switching on when someone else is working on the shower.

16th Ed regulations were in force 10 years ago, so yes.

This is in reply to Owain's message 12/13 but I get a fault message when I try to respond directly to either message.

I have just re-read BS 7671 (latest Brown cover edition) and cannot find any reference to such a requirement, only to a general requirement to reduce the risk of inadvertant re-connection of an isolator (Sections 461, 462 and 537). Maybe I have missed it - can you quote the reference please?

Incidentally, I have also checked back on the installation instructions for a Wickes shower and a B&Q shower that I installed 5 years and 7 years ago and there was no mention in these instructions of such a requirement either.

CRB

[Owain]

Inadvertant reconnection of an isolator would cover it, as would good practice.

For motors, Electricity Regulation 11 and IEE Regulation (15th Ed) 476-5 referred.

Owain

[crb]

So, as I thought, there is no such specific requirement then, either currently or in the past.

CRB

[John Rumm]

Oh yes there is!

Try 476-02-02

[crb]

John Rumm wrote:

[John Rumm]

He usually is! ;-)

[Owain]

'pology 'ccepted.

Owain