OT: NOT DIY Shower Electrics

[John]

Dear All, At present we only have a shower (pumped mixer) in our En-Suite room and SWMBO would like another shower installing in the main bathroom as we have two young boys who will obviously get older and having a second shower would be beneficial. Due to plumbing restraints it would be more convenient to install an electric unit rather than another mixer valve. I can do all the actual plumbing and siting work but our CU is full so there isn't a spare slot for a shower MCB. The house was built in 1992 so fairly new(ish). What are the options, new CU or swap both up and down the lights onto one MCB and use the (then) spare slot for a shower MCB or something else. I will not attempt the electric work myself but I would like some ideas/feedback before I ask a sparky and get the sucking of air through his teeth!!

Cheers

John

[John Rumm]

Three options really

1) Combine / eliminate an existing circuit to free a way for a new one 2) Install a new CU with more ways 3) Split the feed to the existing CU and install a new secondary CU to provide more ways. 1 is cheap n kludgy, 2 is expensive but the neatest solution, 3 is probably the pragmatic way to go.

[Invisible Man]

Agree 3 looks best. Might want to discuss future proofing with the sparks at the same time. RCDs? Split loads so you do not lose all power or all lights with a single problem?

[dennis]

Does it really cost much more to swap the existing CU rather than add a second? The CU is only about £100 in either case and it doesn't take long to move the cables.

[Dave Liquorice]

2 will only cost you the shell of a larger CU and the shower MCB if the choice of new shell is made correctly.

[David Hansen]

On Thu, 23 Apr 2009 00:33:15 +0100 someone who may be "John" wrote this:-

What are these "restraints"? Assuming that the pump, cylinder capacity and pipework is suitable it may be possible to tee off after the pump and run pipes to a second shower. Obviously both mixers should be thermostatic.

Possibly a lot easier than making way for a new way in the consumer unit(s) and wiring from there to the bathroom.

[John]

The cylinder is in a bedroom cupboard across the hall from the bathroom so the pipework would need to go up into the loft accross the landing and back down again into the bathroom, so the water probably wouldn't flow well (if at all). The pump is only suitable for running one shower at a time so that wouldn't help with easing the jam if everybody wanted a shower at the same time. As the cold water tank (huge) is easily accessable in the loft it would be very easy to tap off the outlet feed and drop a pipe down the stud wall in the bathroom.

Cheers

John

[Tim Downie]

It's a poor pump that can't cope with that small hop. If you use flexible pipework you can eliminate a lot of sharp bends.

For the price of an electric shower and all the wiring upgrades, you could easily upgrade your pump.

You want to run an electric shower from a header tank? They're nomally mains fed. (or did you mean "inlet feed"?)

Regards

Tim

[John]

I am sure the pump could cope quite easily with the 'small hop' but the pump paperwork states only use with one shower and it is already being used by the en-suite shower.

Quite possibly hence the question so I could get ideas from people, thanks

Sorry yes I meant the inlet side of the header tank, I was still thinking about my pumped shower which I fed from the tank outlet!

Cheers

John

[Mark]

I'd install the mixer valve and forget an electric shower.

[John Rumm]

In materials cost there is probably no much in it. It would take longer to replace and retest the full CU than to split the tails with a henley, and add a small shower CU, and test.

Much depends on if you are DIYing or paying for someone's time.

[John Rumm]

It would obviously do any number of showers - just performance would suffer. However one would also need to ensure you have enough water storage capacity to cope with two showers at once.

[Trevor Smith]

You can get self contained power showers, they are no bigger than an instant heat electric and they only require a 15amp electric supply. The one I have has to be fed from a storage tank so if your bathroom is plumbed this way all you need to do is tee into the hot and cold.

[David Hansen]

On Thu, 23 Apr 2009 12:26:10 +0100 someone who may be "John" wrote this:-

The water will be under pump pressure and so will have no trouble in flowing up and over the hall. Even in a gravity fed shower this would be no problem, unless the pipe layout was really convoluted. Bend the bends rather than using elbows if you are worried, but everything will almost certainly be fine either way.

Assuming the same shower mixers, you might find the bathroom shower is a little less powerful than the en-suite one when both are running. I doubt it, but if that is the case then just adjust the isolating valves to balance things out.

You didn't say whether it has 15mm or 22mm connections. The latter would be better, but if they are only 15mm that should still be OK. If it is 15mm, which I imagine is most likely, then

is favourite, if it is 22mm then the favourite might be .

Boys will presumably not be too demanding and find

to be fine.

You didn't say how much hot water storage you have, or how quickly the cylinder can be heated up. That is the final puzzle in finding out whether the idea is a goer.

[John Rumm]

15amp - what is it designed to do, peel your skin off? ;-)

(most of them will draw a small current - typically less than 3A)

Yup, they can work ok, but you still need the hot water storage capacity. Also at best they are "ok", rather than good - you can only expect so much performance from a pump on the far end of a pipe - suck too hard and it just cavitates.

[Mark]

If this is poor it can always be replaced by a modern quick recovery cylinder.

[David Hansen]

On Fri, 24 Apr 2009 11:01:53 +0100 someone who may be Mark wrote this:-

A good time to fit a cylinder with a solar coil, ready for the panel.