Help with choice of bath taps.

[ForestFire]

I'm getting a bath put in to replace a stand alone electric shower. My cold mains is strong but cylinder hot is not so great. I'm struggling to decide what taps would be best for filling the bath as fast as possible. I'd ideally like to be able to have mains pressure cold going in to the bath. Will I need separate taps or could I use this...

http://www.screwfix.com/p/watersmith-heritage-clyde-bath-mixer-tap/7974p

 

[gasmanstu72]

if you have 2 different pressures going they won't mix very well.
your cold main pressure will 'push' the weaker hot out the way and not mix unless you cut the cold down.
it'll be like cracking a safe, you'll be turning down the cold a tiny bit at a time to get the right mix.

seperate taps, or both the same pressure on a mixer is best in this case

 

[ForestFire]

Thanks, think I'll go with seperate taps.

 

[REEMS]

All depends on how much you open the taps as to how they mix we have a victorian mixer on our bath hot is open vented and cold is mains pressure and it works fine.

 

[ForestFire]

I wasn't bothered about temperature, more about flow from hot in a mixer being less than two seperate taps. I'm not sure if it would be but if anyone knows?

 

[REEMS]

All depends on the size of the inside size of the tap wether it is mixer or single what hot water supply have you cylinder or combi, and size of pipes to tap ours is 22mm hot because its copper cylinder and 15mm cold as its mains.

 

[Madrab]

If you have a gravity hot water cylinder then full bore bore ISO's, 22mm pipework from the cylinder to the tap and full bore individual bath taps is the only way to maximise available flow.

 

[dishman]

I am just doing this in my property. Same set-up as you. Gravity hot water and mains cold.

Just ensure the taps you select are rated to 0.2 bar or less. It is a real nightmare finding decent looking taps that are properly rated to low pressure systems. Some say both but in reality are not made for low pressure systems, especially for hot water.

Taps that are quarter turn, rather than the traditional "multiple turns" are usually for high pressure systems, as are those with ceramic washers (from what I have read).

Also, ensure try to avoid flexi piping as this restricts the flow a lot. Look for the widest bore feed into the taps. I think the maximum for a mixer tap is 1/2 inch. I cannot find any larger for basin taps.

Also, check that you do not have any restriction valves on the pipes for each tap. These also have a reduced bore which can affect flow.

In my property I was getting very poor flow. 6l/min vs 18l/min compared the the same set-up next door. I traced the issue to all the things above combining to affect the flow quite dramatically.

These are the only decent looking low pressure mixer taps I could find:

http://www.bathandshower.com/taps/bath-taps/min.-operating-pressure/0.1-bar.html

If you look at the filters down the side, you can select the required pressure. I have gone for the lowest possible.

In the descriptions, these say spindle operated cartridge, rather than ceramic washer, which me think that they are the standard rubber washer type (easier to replace too). Some still look like quarter turn ones though.

This is the other site that helped with looking at low pressure system issues.

http://www.forest.plumbing/why-your-water-pressure-might-be-low-part-2/

 

[ForestFire]

All the pipework will be new so no valves and 22mm. How do you know the bore of the tap itself? Been Looking all day and was just about to order these, would they be suitable?

http://www.screwfix.com/p/bristan-orta-bath-pillar-taps-pair/61255

 

[REEMS]

If it says quarter turn they have ceramic valves inside which has a small opening if you were to get single taps or mixer with rubber washers you would get a better flow, obviously that depends on the height of the water water feed tank.

 

[dishman]

Exactly, some say high and low, but most of the time, if they are just quarter turn, with ceramic washers, they are no good.

If you look at some of the ones that I linked to they say "spindle operated cartridges", which I assume means, multiple turns with rubber washers, which is what you want. I have emailed the company to check though.Other taps on their site specifically state "ceramic washers". So there is a difference between "ceramic washers" and spindle operated cartridges".

From what I have read recently, full bore means no restriction. So for 22mm pipe, it is the full 22mm, minus the thickness of the pipe and connections maybe.


I think traditionally, supplies to baths have 22mm. Basins have 15mm.

But, if you notice, on mixer basin taps the connecting pipes thin quite a lot ( I assume to fit two pipes into one outlet). So for a mixer taps the supply is via a short amount of 1/2" pipe which equates to 12mm.

Baths are different as their mixer taps (on many baths) come together from two separate taps. So they can still have a full 22mm supply each.

So for a low pressure system, any basin mixer tap will reduce the flow a bit, just from the pipes going into it.

The flexi pipe , looking at the link i sent, are even worse. They restrict the diameter to 8mm.

I do not think a basin mixer tap with 15mm supply exist, as I said, due to space requirements.

 

[ForestFire]

I get a decent flow to the basin which has ye'oldie taps that screw round and round. I would just buy the same again but more modern if it means good flow. But I don't know where to buy such taps.

 

[dishman]

See my post above, just posted it. That tap site I found seems to be one of the few that has good low pressure taps. Have emailed them to check - will let you know their response.

 

[ForestFire]

Thanks dishman. What about nationwide stores anyone? Most of the websites I look at have a ridiculous postage to where I live in scotland so I don't like giving them any business!! Plus it means waiting around for delivery & possibly having to take time off work.

Just noticedThat Site Bath and shower.com doesnt post to me!!!!

 

[dishman]

I trawled them, and cant find any, other than very simple cheap stuff. I guess there is not enough of a market, or, people just fit the wrong taps and live with the crappy flow.

I would be interested too if any nation wide stores have a proper low pressure range.

Maybe ebay? But there is always a quality risk with things like this.