New bathroom questions.

[happyhacker]

I am fitting a new bathroom and would like advice on:

1. The mixer shower requires even pressure inputs so do I need 2 x 22mm hot and cold or would 22mm hot and 15mm cold (from loft tank) do?

3. Currently all cold is mains. Which taps should have cold from tank?

4. The basin has a combo tap - should this be tank supplied (not mains)? But then it's not drinking water!

5. Should the loo be mains (or tank cold to reduce condensation on the cistern)?

 

[echoes]

I am not a plumber, but...

1. The mixer shower requires even pressure inputs so do I need 2 x 22mm hot and cold or would 22mm hot and 15mm cold (from loft tank) do?

If you have a low head (= low pressure) from your tank, then 22mm will at least give you a better flow than 15mm. Better to use 22mm for each, and dedicated feeds. Would also make it pump-ready should you ever want one.

3. Currently all cold is mains. Which taps should have cold from tank?

Better to feed any mixer taps with equal H & C pressures. No taps need to be tank fed but may work better if they are, and in interests of having washing water available if there is water-works.

4. The basin has a combo tap - should this be tank supplied (not mains)? But then it's not drinking water!

Again, tap will work better with equal pressures BUT it is very convenient to have potable water at the basin for teeth cleaning and late-night glass of water.

5. Should the loo be mains (or tank cold to reduce condensation on the cistern)?

Either - but condensation is more likely with mains, especially if the bathroom gets humid.

If it were me, (and I have a similar project soon!) I would have the bath and toilet tank fed, and the basin mains fed and choose my basin tap(s) carefully. This gives advantage of potable water upstairs, mixer tap over bath, reduced cistern condensation and bath and loo-flushing ability should the mains water supply ever be interrupted.

 

[John506]

It all depends on the system you want.

Direct
Everything fed from the mains.

Indirect
Only kitchen tap fed by mains, everything else fed from a cold water storage cistern.

You can put a pressure reducing valve, or a partly closed gate valve, or anything similair to balance the pressures, so pipe sizing isn't a great issue here.

If you have a cold water storage cistern installed, then only the kitchen tap should be fed from the mains. So your basin and toilet should be tank fed.

 

[Nige F]

Echoes v John I`m with Echoes :

 

[seco services]

Echoes v John I`m with Echoes :

Yes i agree.

johns a little bit misleading.

 

[John506]

Echoes v John I`m with Echoes :

Yes i agree.

johns a little bit misleading.

I try my best

 

[Whitespirit66]

Yes, Echoes for me too.

OP, couple of points -

1) If using mixer taps/showers, these are normally happier with balanced supplies, ie. either both H and C low pressure/tank fed or both H and C mains/pumped.

2) If using mixers and decide on low pressure, make sure the mixers are a type that is suitable for low pressure

 

[happyhacker]

Thanks, your comments lead me to the conclusion that the bathroom basin (separate taps) will be mains and bath taps/shower, mixer and toilet will be tank. I will leave the cloakroom as hot/mains but will check the model of mixer tap and fit a stop in the hot supply if necessary.

 

[echoes]

OP, some mixer taps will tolerate unequal pressures on hot and hold, and there is always the option of a restrictive valve or a PRV for your basin. Not an elegant solution though - I haven't seen a PRV which will throttle the mains down to the 0.2 bar typical at a basin mixer, but they might exist.

My kitchen mixer tap has low pressure hot, but having 2 tap levers is easy to adjust, and the cold iso. valve is a cheap restrictive one which helps a tiny bit! Its those single lever mixers which tend be hard to get the right temperature with unequal pressures, especially if your mains pressure is high. It's one of those function vs. aesthetic decisions.

Downstairs is somewhat less of a problem since there is another 2m of head on the hot.

(Having said all that, my shower is a mains/PRV cold and pumped hot with check valves present and decent thermostatic mixer. It works very well, despite not being preferred solution, but alternative was to remove ceilings to get a 22mm cold feed in...)

Best of luck with it all!

 

[happyhacker]

Interesting echoes, thanks.