mira sport shower problem

Discussion in 'Plumbers' Talk' started by audi-evo, Apr 4, 2006.

  1. audi-evo

    audi-evo Active Member

    i have had a new mira sport 9.5kw shower fitted, as the old one was lower power i had a spark rewire it.
    He did the shower swap on the understanding the old plumming would be used (so straight swap)
    The new shower gets either very hot or cold and won't maintain a steady temp.
    The water pressure seems ok ie when you turn cold taps on lots of water comes out of the cold taps very quickly.
    Any ideas?
    My thoughts are the origional pipe set up is at fault.
    It has a T piece from the cold bath supply pipe and an elbow connected to that on a very short (50mm) pipe, then straight up to the shower.
    Could this be the problem?
  2. sherlock

    sherlock New Member

    have you checked handset for blockages and the filter.
    water pressure needs to be within 0.7 bar and 10 bar.
    hope this helps.
  3. tgs

    tgs New Member

    The supply pipe seems perfectly reasonable. I would suspect the shower as being faulty if, as you say, it is cycling from hot to cold and back again. This is known as hunting and is a result of the control loop not being correct. It is also a symptom of the water pressure being just on the verge of adequate.

    Is the bath cold water supply from the mains or from a cold water tank? It could be that the older shower could just cope with the low pressure but the newer one being higher power couldn't.

    Baths quite often are supplied from the cold water tank rather than mains water even if the rest of the bathroom has mains water. They are usually (but not always) supplied by 22mm pipe if they are so supplied. Does the pipe reduce in size at the T piece?

    If the water supply is mains pressure and the pressure is maintained above the minimum pressure for the shower then there should be no problem.

    Incidently, Mira do not list a 9.5kW sport model either 7.5, 9.0 or 9.8. They also list thermostatic and non-thermostatic. Which one is yours?
  4. audi-evo

    audi-evo Active Member

    I can't remember the size, i know the old one was 7.5kw.
    I bought the mira sport because thats what the old one was and i thought the swap would be easier.
    I bought it from plumb centre. (there are no markings on the case to tell you the power)and i have binned the box.
    I didn't get the 10+kw but it could be either the 9 0r 9.8kw.
    The bath is direct from the mains and the T reduces from 22>15mm then 15mm elbow, the straight 15mm to shower.
    I don't really know the water pressure but by simply turning on cold tap at the basin it seems very good.
    The problem i have now is the spark has left the area so i can't go back to him.
    How do i tell if it is the plumbing or the shower unit.
    I don't fancy taking it out and returning it to plumb centre for them to tell me it is fine and the problem is in my house.
  5. could you call Mira under Guarentee??
  6. tgs

    tgs New Member

    OK I have a feeling that my suggestion about the pressure is correct. This is because of you said the pipework reduces from 22mm to 15mm. This suggests the bath is run off the cold water tank and not the mains. As I said, the basin is sometimes run off the mains even though the bath is run off the cold water tank. It is the pressure and flow at the bath you have to be concerned with not the basin. Also a nice gush of water out of the tap does NOT mean that the pressure is OK for the shower.

    First up, DO NOT USE THE SHOWER until you are certain that the pressure is OK.

    Second, simplest option is to get a plumber. This is a plumbing issue and he will be able to sort out the pipework for you.

    Third, if you don't want a plumber, then you will have to trace the pipework and check that what is connected to what. If my guess is correct then you will have to close off the current connection at the bath and transfer it to either the basin or wc. It is possible that the entire bathroom does not have mains water in which case you will have to tee off at the cold water tank in the loft and bring a pipe down to the shower.
  7. sherlock

    sherlock New Member

    Re: mira sport shower problem
    Posted: Apr 4, 2006 11:40 PM Reply


    OK I have a feeling that my suggestion about the pressure is correct. This is because of you said the pipework reduces from 22mm to 15mm. This suggests the bath is run off the cold water tank and not the mains. As I said, the basin is sometimes run off the mains even though the bath is run off the cold water tank. It is the pressure and flow at the bath you have to be concerned with not the basin. Also a nice gush of water out of the tap does NOT mean that the pressure is OK for the shower.

    First up, DO NOT USE THE SHOWER until you are certain that the pressure is OK.

    Second, simplest option is to get a plumber. This is a plumbing issue and he will be able to sort out the pipework for you.

    Third, if you don't want a plumber, then you will have to trace the pipework and check that what is connected to what. If my guess is correct then you will have to close off the current connection at the bath and transfer it to either the basin or wc. It is possible that the entire bathroom does not have mains water in which case you will have to tee off at the cold water tank in the loft and bring a pipe down to the shower.

    wot do you mean your suggestion about the pressure, it was mine first!! ;)
  8. audi-evo

    audi-evo Active Member

    Ok it's late but i'm off to rip the bath pannel off and take a good look. I could be talking 8ollox about the pipes so i'll go and double check.
    BRB!
  9. audi-evo

    audi-evo Active Member

    May take a while, sons just gone in the bath!
  10. dont worry, sure he wont mind you doing a spot of bathroom destruction!
  11. sherlock

    sherlock New Member

    tell your son to be quick, hes keeping us all up!, weve to be up for work in morning, o no im on holiday.
  12. audi-evo

    audi-evo Active Member

    Ok bath pannel off.
    It isn't 22mm (i could only see the bit to the bath tap)
    There is a 15mm pipe from the main it runs behind the bath (below the taps) and has a T this goes up 75mm then has a T to the left and the top converts to 22mm for the bath tap.
    The T to the left has 50mm of 15mm pipe then an elbow then straight up to the shower.
    The bath pannel also now has a crack in it because it's midnight and i'm getting pi55ed off with it!
  13. sherlock

    sherlock New Member

    have you checked handset for blockages and the filter.

    other than that i reckon you have a dodgy shower as tqs suggests.
  14. how does the shower perform without the head on the hose?
  15. audi-evo

    audi-evo Active Member

    i'll try it without the head in a min, cheers
    (i need a wash anyway)
  16. sherlock

    sherlock New Member

    try turning the temp knob anti clockwise to increase flow of water, the water could be to hot causing the appliance thermal trip to operate. causing the heater to turn off and on.
  17. sherlock

    sherlock New Member

    it cant be low flow i dont think, as it has a built in low pressure warning led. it would be lit.

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