Mira vie 10.8 shower pressure problem

[Andrew Haughton]

I have worked flat out to install a new bathroom before xmas only to find the shower runs cold, (no power problem).
Here's the way I did it and I hope other relevant facts:
Its a 1st floor bathroom in a small 10 year old house. The shower is above a bath with 22mm mains supply ( since we had a combi boiler installed recently.) There is a pressure adjustment valve (showing just under 1 bar, I think) on a 1/2 inch pipe in the loft but I imagine this feeds only the ensuite on the other side of the house as if it goes to the bath then the pipe thickness seems wrong. So far as I can see the cold flow in the bath is a good healthy rate. The shower above the bath is connecetd via about 6 of 1/2inch copper which has just 2 hand bent bends in it - about 6" radius so minimal resistance I would imagine?
I think the unit is faulty and so does my electrician who connecetd it up to the consumer board but as its me who supplied it and plumbed and wired it, its up to me from here. Mira will charge me to come and sort it out if its a water pressure problem. The pressure according to mira should be no less than 7 bar (or is it 0.7 bar?, I hope you will know!)
My question therfore is whether or not it could be a pressure problem and what I can do if it is.
Thanks
Andrew

 

[mikhailfaradayski]

does the shower have any indicator lights on it, e.g. half/full power/overheat/pressure ?

if so, what do they tell you?

 

[ban-all-sheds]

as its me who supplied it and plumbed and wired it, its up to me from here.

Did you commission it according to the manufacturer's instructions?

Did you get an EIC for the electrical work?

The pressure according to mira should be no less than 7 bar (or is it 0.7 bar?

I doubt that it's supposed to be over 100psi!

 

[electronicsuk]

Its a 1st floor bathroom in a small 10 year old house. The shower is above a bath with 22mm mains supply ( since we had a combi boiler installed recently.)

I don't understand. You make out that you have an electrically heated shower, yet you also mention a combi boiler and 22mm feed.

There is a pressure adjustment valve (showing just under 1 bar, I think) on a 1/2 inch pipe in the loft but I imagine this feeds only the ensuite on the other side of the house as if it goes to the bath then the pipe thickness seems wrong.

It might be involved in feeding a mixer tap somewhere, although I can't see why you would need it when you have a combi boiler. Usually, there's only a need for a pressure reducing valve where the hot water is fed from a vented system under gravity pressure, and the CW is mains fed, therefore it is good practice to balance the pressure on both the hot and cold sides of a mixer. Perhaps if this was there prior to fitment of the combi boiler, it is now defunct.

I think the unit is faulty and so does my electrician who connecetd it up to the consumer board but as its me who supplied it and plumbed and wired it, its up to me from here. Mira will charge me to come and sort it out if its a water pressure problem. The pressure according to mira should be no less than 7 bar (or is it 0.7 bar?, I hope you will know!)
My question therfore is whether or not it could be a pressure problem and what I can do if it is.

There will usually be at least some indication on the unit if there is low water pressure.

 

[seco services]

this shower won't operate on less than 0.7 bar mains water pressure.
ideal pressure willbe 1 bar or above.

you say you have a pressure reducing valve in the loft set to under 1 bar is this the same pipe that the shower is fed from ?

and why is it set to under 1 bar ?

sounds like your pressure is to low and not activating the pressure switch in the shower.

 

[martinxxxxxx]

Are you a plumber?

This def sounds like a plumbing problem to me.

Cold water supply unregulated in = hot water out is the norm.

If you cannot be sure you have this setup, get a plumber to have a look. It will be cheaper than getting the manu man out or dismantling the system.

Are you an electrician? If not, do you consider it safe to be working where people are going to be wet next to "high voltages" (sic). And are you aware you maybe liable under law both criminal and civil for your actions. Even if it all works.

It worries me and should you that it does not work. My advise is to get some help on both the electrical and the plumbing side.

Sorry if any of this sounds harsh, it is though my advice.

Martin

 

[Andrew Haughton]

Thanks to Electronicsuk and others for advice so far.
Should have explained there is already another shower running off the combi boiler and as we often have more than 2 people getting ready for work at the same time and that was the reason for the extra shower, it had to be electric as I'm sure most will know - the boiler would not cope with 2 showers or so we were advised very strongly by 2 professional plumbers.
We originally had cistern and HW Cyl removed, combi installed, found taps in ensuite were very fierce so plumber put in The pressure reduction valve. Seemed a good idea to me and worked. And proves that the incoming mains pressure is very high. As its on a 1/2 inch (15mm) pipe I can't imaginer it serves the 3/4inch (22mm) pipe in the bathroom from which I, myself, have connected the shower, via a 1/2 inch (15mm)pipe.
Its a mira vie shower and there is no indicator light other than the on/off switch.
What I don't get is how can the incoming mains pressure be as high as it obviously is and yet the shower pressure is too low.

 

[seco services]

i would say that the 22mm connects to the 15mm somewhere.
its very common on systems that have been converted from gravity systems with cylinders etc to mains pressure combis.
the pipework under the baths etc don't get changed from the old 22mm
as with new builds we always supply baths etc with 15mm when mains pressure.

try opening the pressure reducing valve to 2 bar and try it.
theirs no need to have it as low as 1 bar anyway.

or pressure test the pipe what feeds the mira shower
which should always be done before fitting any electric shower anyway.

 

[electronicsuk]

I think your best bet right now would be to turn on the shower, set the temperature control down to minimum, and see what sort of flow rate you achieve. If the flow is good, it's unlikely to be a pressure problem and more likely a fault with the shower internally. If it's poor, you should be investigating the plumbing.

I think we can assume you have power at the unit, otherwise you wouldn't be able to turn it on, although a high resistance joint that doesn't allow enough current to flow in order to run the heating elements still isn't out of the question.

 

[Andrew Haughton]

Thanks to everyone for advice.
Seco services and electricsuk - both helpful. It really does look like the plumbing is snaking around alloever the place so I will re route the supply pipe. I wish I had looked more carefully to startwith.
Martinxxxxx, No I'm not an electrician. my original post said I had the system connected up by an electrician, obviously tested and happy with the wiring which I put in. I have DIY wired a house, several kithchens, my workshop and always got it checked by professionals and rarely been faulted.

 

[martinxxxxxx]

Did the electrician give you a cert for his install/ checking service? If he did there should be a figure for Zs for the line on the schedule of tests for the shower circuit. And also figure for r1+r2.

Can you tell us what these figures are please?

Personally if I commissioned a new shower and it did not function I would stopping around till it did or I could confidently say remove it and take it back to shop for replacement. I wouldn't risk leaving it live with an unknown fault for the customer to solve.

I am trying to help here.

Martin

 

[seco services]

Did the electrician give you a cert for his install/ checking service? If he did there should be a figure for Zs for the line on the schedule of tests for the shower circuit. And also figure for r1+r2.

Can you tell us what these figures are please?

Personally if I commissioned a new shower and it did not function I would stopping around till it did or I could confidently say remove it and take it back to shop for replacement. I wouldn't risk leaving it live with an unknown fault for the customer to solve.

I am trying to help here.

Martin

ffs give it a rest will you.
its nothing to do with a faulty shower at all its a pressure issue
as he said he commissioned the shower not quite rocket science.

got f*ck all to do with what the cert says
personally couldn't give a toss about the cert or your f*cking regs.
when its a plumbing issue.


surely if your trying to help you'll know its got nothing to do with an electrical problem.

maybe this post should be put in the right section plumbing where it belongs.

 

[electronicsuk]

ffs give it a rest will you.
its nothing to do with a faulty shower at all its a pressure issue
as he said he commissioned the shower not quite rocket science.

got f*ck all to do with what the cert says
personally couldn't give a toss about the cert or your f*cking regs.
when its a plumbing issue.


surely if your trying to help you'll know its got nothing to do with an electrical problem.

maybe this post should be put in the right section plumbing where it belongs.

FFS maybe you plumbers should get over your f*cking attitude problems and post your s*it over in the plumbing forum where this sort of language belongs. And perhaps learn to punctuate at the same time.

Sorry, but there really was no need for that. I think we have already established it is either a pressure problem or a fault with the shower itself, and the OP has already stated that they are investigating the plumbing.

 

[martinxxxxxx]

ffs give it a rest will you.
its nothing to do with a faulty shower at all its a pressure issue
as he said he commissioned the shower not quite rocket science.

Is it?

got f*ck all to do with what the cert says
personally couldn't give a toss about the cert or your f*cking regs.
when its a plumbing issue.

Then they don't matter then.

But if water is coming out, but it is not getting hot, and it is supposed to use electricity to heat it- Do you not agree the electricity could play a part in why it is not working?

surely if your trying to help you'll know its got nothing to do with an electrical problem.

As above, I would work with the plumber (if one is there, and can speak in plain english) on site to solve the problem.

maybe this post should be put in the right section plumbing where it belongs.[/quote]

 

[Andrew Haughton]

Due to advice from many people on this brilliant website I found a solution to my shower not working and I am no longer depressed and down in the dumps and neither is my wife and step-son .....
Thanks to electricsuk, seco and to Martin who gave stern but actually wise advise. My electrician has to bring parts after xmas for other aspects of work he is doing so certificates not yet issued but I will know what to look for thanks to Martin. Happy xmas to you guys and I promise not to be so touchy next time!
Andrew