Water Pressure On Mixer Taps.

[johnny37]

Why is it virtually impossible to balance the hot/cold output on my bath mixer tap? Is there some sort of balancing mechanism missing?

[The Builder]

I can only take a guess, Johnny, as I don't know what system you have.

Perhaps you have hot water from an immersion cylinder (low pressure - gravity), and your cold is direct from the mains (high pressure)

Without a really good thermostatic mixer, that's always going to be difficult to control.

[buildersmate]

Is there equal hot and cold pressure? In other words, are both taps either fed via a cold water tank in the loft, or perhaps both are on mains pressure?
If your cold is on mains pressure but your hot isn't, you will struggle. Putting in a flow restrictor to the higher pressure may help, but these restrict flow, not pressure.

[buildersmate]

Snap, boss.

[johnny37]

yep, its cold/mains and hot/cylinder.

[buildersmate]

Convert the cold to feed it from the same (cold tank) source as the hot.
A thermodynamic unit may work if the differential is not too great.

[buildersmate]

Thermostatic

[HansUrbancka]

Why are you concerned about balancing the flows. I hope you are not trying to run a shower fixing which could be dangerous.

Hans.

[buildersmate]

Because he can't get a tepid shower. With a mains fed cold supply, the control will need to be right over the H side, and shifting the lever a microscopic amount Ali shift the temperature of the water from very cold to too hot.

[snags]

Something like this? :)

http://i151.photobucket.com/albums/s156/snagged_01/shower.png

[The Builder]

Well, I've been on here for years, and that's the first time I've seen Snags in the DIY section........... he must have become domesticated ;o)

Going back to BM's restrictor idea, rather than a flow regulator, you could try a mains pressure reducer/regulator on the cold feed to the tap only.

It's the kind of thing that's fitted under the kitchen sink where mains pressure is far too high. If I'm right, that shouldn't restrict flow too much.

[The Builder]

http://www.honeywelluk.com/products/Valves/pressure-reducing-valves/D05-Pressure-Reducing-Valve/

Without doing the Maths, I'm not sure that this could reduce the pressure enough to match a simple gravity head pressure though.

What do you think, BM? ............... or Snags, for that matter? ;o)

[buildersmate]

Yes I think it would work. Need to experiment with the setting at around one bar of pressure.
Just need to find a place to access the supply pipe and fit the device.

[The Builder]

1 bar? That sounds Ok BM. I think those reducers can do that :o)

Should be enough room under the bath.

[HansUrbancka]

Am I missing something because I am unable to read where johnny37 has said anything about a shower being involved. He made reference to a Bath Mixer Tap and I said...." I hope you are not trying to run a shower fixing which could be dangerous."....I had in mind a shower head on the end of a rubber hose; which is difficult to safely control temperature.

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Hans.

[Old_Geezer]

A shower is one of the main reasons for having a mixed arrangement over the bath. It's how my shower works. It just needs a steady hand and a willingness to adjust as required.

And is why I suspect my local water provider of reducing mains pressure a few months back. May not be the only possible cause but suddenly the default tap lever position changed !

[Old_Geezer]

...a mixer arrangement...
as typed >:-(

[The Builder]

Hans, I think we are assuming that he has something like this .........

http://www.homebase.co.uk/en/homebaseuk/bathroom/bathroom-taps-and-mixer-taps/bristan-sway-bath-shower-mixer---chrome-858248

Maybe not, but I wouldn't have thought that balancing the temperature when simply filling the bath is quite so necessary.

[HansUrbancka]

@The Builder.....I see what you mean. Perhaps johnny will enlighten us and tell us more. Meanwhile, I'll drift back to the Technology Section. :-)

Hans. ☺☺☺

[johnny37]

sorry for the delay in replying! What i actually wanted is a mixer tap in the garden to hose down my adorable springer, molly. I have mixers on the kitchen sink and the upstairs bath. The kitchen tap is never used as a mixer. The bath is only rarely used but is a pain getting it balanced if eg you just want to wash your hair. There is only one outdoor mixer on the net and it costs approx 120 quid. And would it work? Not according to your comments above. I had the plumber in for a few jobs and got him to fit an outdoor hot tap. Hozelock must do some sort of connector. I will try it out and let you know.

[bhg481]

Hozelock make a "Y" connector/splitter. You can connect a short hose to your hot tap and the Y connectoer, another short hose to the cold tap and the Y connector and then your long hose to the third port on the Y connector.

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