Can electric and mixer showers be combined

[ban-all-sheds]

Redring do a 12kW one - if that's at 240V (almost certainly is) then a 50A circuit is needed - no harder to sort out than a 45A one for a 10.8kW shower.

 

[JohnW2]

Yep, I'm thinking you'd only get a dribble out of the middle of it?? No where near the same as you'd get from a properly installed hot water system.

I guess it depends upon what you're comparing with - if with a pump-assisted rain head, you may be right. However, if gravity-fed from a conventional hot-water system, the pressure available for a rain head near ceiling height in an upstairs bathroom of a 2-storey house is usually pretty pathetic.

Kind Regards, John.

 

[ban-all-sheds]

AIUI with rain heads it's flow rate which is the main thing, not pressure - they're meant to be soft & gentle.

 

[JohnW2]

AIUI with rain heads it's flow rate which is the main thing, not pressure - they're meant to be soft & gentle.

Hmmm - but I=E/R (I=V/R for the youngsters!) works for water the same way as for electricity, doesn't it?

Kind Regards, John

 

[ban-all-sheds]

[disclaimer]IANAP[/disclaimer]

However, if gravity-fed from a conventional hot-water system, the pressure available for a rain head near ceiling height in an upstairs bathroom of a 2-storey house is usually pretty pathetic.

I'd not be surprised if you fed one like that with 2" pipes that it would work fine.

 

[JohnW2]

However, if gravity-fed from a conventional hot-water system, the pressure available for a rain head near ceiling height in an upstairs bathroom of a 2-storey house is usually pretty pathetic.

I'd not be surprised if you fed one like that with 2" pipes that it would work fine.

Maybe - but I suspect that 99% of the total resistance would be that due to the holes in the shower head, so that increasing the size of the supply pipe would make little difference. I certainly have come across pretty pathetic flow from gravity-fed showers, even with showerheads at 'ordinary' heights - and I guess that's why pumped showers were invented!

Kind Regards, John.

 

[Ron7]

Hi, I have just come across this forum whilst searching the feasability of having both an electric shower and mixer shower in the same cubicle. I currently have a 1200 by 800mm shower in between walls, with an aqualisa quartz digital pumped system fed off the hot & cold water tanks. (no combi in place). I am concerned about running out of hot water every morning when the family showers, and therefore thinking of placing an electric shower on the opposite wall to the aqualisa, on the 800mm walls, 1200 mm apart. (both showers will have hoses on sliding rails). The beauty of this is that in summer the electric would be used more than the mixer, and I predict the mixer more so in winter when the heating is used more greatly along with regular heating of the hot water tank. Also, if the aqualisa is in use and the hot water runs out, it is easy to walk to the opposite side of the shower and turn on the electric shower. I am a DIY'er, and the tradesmen I have discussed this with so far do not see a problem, other than the mention of running both showers regularly to remove the risk of legionella, in particular with the aqualisa mixer. I welcome other views and comments. Thanks, Ron

Probably more of a plumbing question. Electrically there's no theorectical or safety problem, providing the regs are adhered to,

I have to say that I would not be all that comfortable about the electrical side of things. Whatever the IP rating of the electrical shower may be stated to be (and having seen inside many of them), I'm not sure I would be totally comfortable with a continuous high pressure divergent spray of water coming down from near ceiling onto the electrical shower unit. That would be far more 'testing' of the IP rating than the occasional brief sprays that are usually encountered from the electrical shower itself.

Kind Regards, John.

All - Thank you for your quick responses. Pretty much what I thought and hence why I could not find any references on the internet. Reason for proposal had been to avoid running out of hot water from the cylinder if in heavy demand - e.g. bath and multiple showers and hence have the electric shower as a back up, but in the same cubicle.

Not yet spoken to electrician who will be doing the bathroom, but no point in asking him to quote for electric shower if all we can have is the rain head on conventional shower. Clearly to do what we were thinking may be possible would require a shower with a much higher IP rating than normal.

Cheers

 

[JohnW2]

I am concerned about running out of hot water every morning when the family showers, and therefore thinking of placing an electric shower on the opposite wall to the aqualisa, on the 800mm walls, 1200 mm apart. (both showers will have hoses on sliding rails). I welcome other views and comments.

The only (small in your case) issue is the one I mentioned in this thread, and which you quoted in your message - namely that the Aqualisa could possibly drown the electrical shower unit with a speay of water (which would make me nervous, no matter what the stated IP rating) - but with 1200mm between them, that's probably not much of a concern.The 'risk' would, of course, be lower if you could have both showers on the same wall, since the Aqualisa woul then usually be directing its spray away from the electric shower unit, rather than potentially towards it. However, I imagine that what you propose would probably be OK.

Kind Regards, John.

 

[ban-all-sheds]

Maybe - but I suspect that 99% of the total resistance would be that due to the holes in the shower head, so that increasing the size of the supply pipe would make little difference.

Maybe.

As I said, IANAP, but I can't rid myself of the intuitive feeling that if I had a tank of water 50cm or so above my head, with a 2" pipe in the bottom feeding a rain head, and I opened the valve, I'd get a fair bit of water coming out.

 

[ban-all-sheds]

the tradesmen I have discussed this with so far do not see a problem, other than the mention of running both showers regularly to remove the risk of legionella, in particular with the aqualisa mixer.

Neither shower stores hot water, so running them, or not, will do nothing one way or the other about legionella.

 

[Ron7]

I am concerned about running out of hot water every morning when the family showers, and therefore thinking of placing an electric shower on the opposite wall to the aqualisa, on the 800mm walls, 1200 mm apart. (both showers will have hoses on sliding rails). I welcome other views and comments.

The only (small in your case) issue is the one I mentioned in this thread, and which you quoted in your message - namely that the Aqualisa could possibly drown the electrical shower unit with a speay of water (which would make me nervous, no matter what the stated IP rating) - but with 1200mm between them, that's probably not much of a concern.The 'risk' would, of course, be lower if you could have both showers on the same wall, since the Aqualisa woul then usually be directing its spray away from the electric shower unit, rather than potentially towards it. However, I imagine that what you propose would probably be OK.

Thanks John, and I understand exactly what you are saying. The head off the aqualisa, albeit a hose on a rail, would be pointing downwards and some way off the electric shower box. The only water I guess that would hit the elctric unit would be any rebound spray off our head or shoulders, but having said that the same rebound spray would arise off the electric shower head. I just need to be self-assured really that what I am thinking will work ok, and most importantly be safe. Thanks again. Rgds, Ron

Kind Regards, John.

 

[ban-all-sheds]

No replies so far to this:

//www.diynot.com/forums/plumbing/alternative-supplies-for-a-mixer-shower.331219/

 

[JohnW2]

Maybe - but I suspect that 99% of the total resistance would be that due to the holes in the shower head, so that increasing the size of the supply pipe would make little difference.

Maybe. As I said, IANAP, but I can't rid myself of the intuitive feeling that if I had a tank of water 50cm or so above my head, with a 2" pipe in the bottom feeding a rain head, and I opened the valve, I'd get a fair bit of water coming out.

You might do - it's purely a question of the vertical distance from tank to rain head and the characteristics of that rain head (essentially the size and number of 'holes'). My point was that, however much water you had coming out with your (presumably short) 2" feed pipe, I'd expect much the same with a 15mm pipe, since the resistance of the entire system, hence flow for a given pressure head, will be dominated by the shower head, not the pipework.

... and, as I said, I've certainly enountered some pretty pathetic flow rates from gravity-fed showers, haven't you?

Kind Regards, John.

 

[JohnW2]

Thanks John, and I understand exactly what you are saying. The head off the aqualisa, albeit a hose on a rail, would be pointing downwards and some way off the electric shower box. The only water I guess that would hit the elctric unit would be any rebound spray off our head or shoulders, but having said that the same rebound spray would arise off the electric shower head. I just need to be self-assured really that what I am thinking will work ok, and most importantly be safe. Thanks again.

AsI said, I think that's the only potential issue and, from what you've described, I think it would be OK - probably not really any greater risk than that due to water hitting the shower unit from the electrical shower itself.

Kind Regards, John.

 

[ban-all-sheds]

... and, as I said, I've certainly enountered some pretty pathetic flow rates from gravity-fed showers, haven't you?

Yup.