Bath mixer tap - poor hot flow

Discussion in 'Plumbing and Central Heating' started by wouldbplummer, 3 Jan 2006.

This topic originated from the How to page called Fitting new taps.

  1. wouldbplummer

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    I've just replaced my two single bath taps with a new shower mixer tap (1/4 turn with ceramic disc, suitable for low and high pressure systems). The problem is that this new mixer tap has very poor hot water flow (takes ages to fill the bath even a small way). I have excellent hot water pressure on all other hot water taps and this was also true with the former single bath taps. Also cold water pressure seems to dominate and push back the hot water when both the hot and cold are being mixed together on the new tap. Would appreciate some advice please! Would a return valve help on the hot side or is there anything I can do to the tap valve? Or have I just got to expect this with a mixer tap? Thanks!
     
  2. bab

    bab

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    r u sure its suitable 4 low pressure. what make is it . dit u use flexi pipes under bath. is there a filter on the spout outlet. u'll never mix mains cold with low pressure hot on a cheap bath mixer. it should hav low pressue cold to it to match the hot pressure. Then u could turn on taps go to pub 5 beers then back for a bath half full a water,
     
  3. wouldbplummer

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    thanks for quick reply, didnt have to change any pipes my old tap conectors
    fitted strait on, there is a filter on end but sure thats not prob,didnt know u needed gravity presure hot and cold who thinks of that when thay fit? so thers no easy way out of this mess then just a ****ty design falt on the tap i think, i could go down pub all week before i had water deep enough to float my veg!.


    Here's a link to the exact tap I bought (paste into address bar)http://www.taps.co.uk/applogic/productinline/579/alpha_basin_taps_&_bath_shower_mixer.html
     
  4. Nige F

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    Non return valve on hot would make it worse :eek: Who told you it was for low pressure :?: They should be wearing it :evil:
     
  5. ChrisR

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    PLUMBERS do.

    The mixer may have check/one-way valves built in. If not you need to add them both sides. If it does, take the HOT one out and put a 22mm one in the pipe instead. The integral ones have tiny bores.
     
  6. wouldbplummer

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    can i just remove the integral check valve on the hot side and try, is it easy to remove? if the tap has not got any where can i get and how much. do i need in both hot and cold or just 22mm hot side?
     
  7. tomii

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    Hi, did you manage to resolve this problem? I'm also having the same problem with my new mixer tap which replaces the two single old tap. The hot water on the mixer is very weak but the cold is very strong, how can this be corrected? any suggestion would be most appreciated.
     
  8. TicklyT

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    Looking at the info posted by the OP, his tap was not suitable for a gravity system - the link he gave quoted a pressure range of 0.5 - 5 Bar. A typical first floor bathroom with gravity fed hot system from water storage tank in the loft above will have a water pressure of about 0.2 Bar , less than half the minimum design pressure.

    For a 'back of a fag packet' calculation, the water pressure in Bar is 1/10th the vertical distance from the base of the cold water storage cistern to the tap outlet.

    Sorry, but Nige F is right.... If a salesman sold you the mixer as suitable for use with a gravity system, then he needs to have some basic laws of physics explained to him with the help of something large and heavy, with some particularly nasty sharp corners to use as a teaching aid.
     
  9. marcopolo

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    Any ideas for names of mixer taps for this set up then?
     
  10. Softus

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  11. Stivino

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    That'll be 10m to a bar then.
     
  12. Softus

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    That's a good enough approximation.
     
  13. Stivino

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    Some things never change.
     
  14. Softus

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    Gravity-induced pressure does though, according to where you are on the planet.

    For example, on the equator the head of water needed to generate 1 bar (not Bar) can be as much as 10.24 metres.
     
  15. Stivino

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    Feeling a bit pedantic today Softus?
    I'm off to watch Lewis Hamilton. C'mon the Brits.
     

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