Plumbing Question

Poor flow on new bathroom mixer tap

I have had 2 bathrooms on the top floor of a three storey house re-done. The water system is gravity fed: cold water tank in loft and hot water cylinder on the top floor adjacent to bathrooms. Old basins had seperate hold and cold taps. Flow was ok. New mixer taps (Marflow phase 4 mini baisn mixer recomended min. pressure 0.2bar) have very poor flow rate for both hot and cold. Builder says he doesn't know why. The existing bath tub still has the old seperate hot and cold taps and these work ok. What can I do?

2 Answers

Best Answer

A common problem with modern mixer taps.

You've got the worse case scenario as your cold storage cistern is giving minimal head to your 3rd floor basin taps which at 0.2 bar require a minimum of 2m head to work properly.

If tap isolators have been fitted then they'll need to be full bore and the copper tap tails that came with the taps should be installed rather than small bore flexi tap connectors.

If all of the above is true then you'll probably be best to choose a different tap, preferably a 0.1 bar type with two taps not a single lever - not ceramic disc.

Quite why your installer doesn't know any of this is a mystery ...

Answered 28th May 2012

Amwell Property Services

Member since 11 Sep 2010

Very much agree with amwell property services, everything they have said is totally correct.
Another solution if you should like to keep with the new taps is to add a straddle tank to the hot and cold supply in the loft, effectively increasing the head by doubling the amount of water pressing down on the supply.

I have used this method several times as an economical solution to poor water pressure and an essential requirement on certain installations of power showers.

You could also re plumb the cold supply to mains pressure and add a really big header to the hot supply to compensate the difference on supply pressure, but the most economical and sensible option long term is to replace the hot system with a combi or mains pressure hot water tank, 30k minimum for a good flow rate which most modern mixer taps are designed for.

Hope this helps

Kindest regards

Hi there,
I know you have sent a request for me to quote, and I wish I could, but being based just outside of york I would be very uneconomical to carry out the repair.

If you need any further advice, however, I am very happy to help at a distance should you feel you are being given incorrect advice or more importantly feel being fleeced.

Hope you find someone trustworthy through Mybuilder and am here if you need any more advice.

Kindest regards

Answered 28th May 2012


Member since 24 Apr 2012

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