do modern mixer taps reduce water flow

[bobby_la_mesma]

Dear Forum

I have just changed my bath and basin taps from individual hot and cold to a modern mixer tap. The problem now is that the water flow seem to be significantly reduced with both hot and cold tap on. Is there something in modern mixers that is causing this? The water pressure seemed ok before, although not amazing.

This is in a upstairs bathroom with hot water tank on adjacent wall and cold water storage tank in the loft. I do not have a combi boiler.

Do I have to consider buying a pump?

Any thoughts I would be grateful

 

[DP]

A lot of these taps are meant to be used in conjunction with mains hot and cold. Such a tap will give poor performance when fed from storage derived outlets.

 

[bobby_la_mesma]

Thanks.

Do you know if I can run the feed off a shower pump?

I am considering buying a new pump for my power shower and would be will to do some re-configuration of pipe work if it is practical.

 

[TicklyT]

Much of the 'designer' brassware available is only suitable for use with high pressure systems , usually at pressures greater than 1 Bar. This pressure is usually available from combi boilers and unvented systems.

Traditional open vented systems with a cold storage tank in the loft etc. etc. usually offer a water pressure of about 0.2 Bar. that's a fifth of the mimimum pressure of many taps on the market. To achieve 1 Bar pressure with a gravity system would mean raising the cold storage tank to 10 Metres ( say 3 floors) above the bathroom taps, which is usually 'a little impractical'.

Gravity systems use larger bore pipework and taps with generously sized waterways to achieve adequate flow with the low pressures available.

Most styles of brassware are available for low pressures somewhere, although the range of prices may differ from cheaper high pressure only taps.

The minimum pressure is usually stated on the packaging of the taps, or in the catalogue blurb.

So the options include:-
Pump the supplies
Replace hot water system with a pressurised system
Replace taps with brassware designed for the system you have.

 

[JohnD]

changing the taps would be the least complicated option

 

[bobby_la_mesma]

Tickly T that was a very well explained answer which I now understand the issues. The taps do say suitable for Pumped systems and make no mention of open vented gravity fed system.

John d thanks also for you easy option


I'll live with the mixer sink because I'm never really going to need amazing flow.

Since I have already decided to buy a new shower pump could I bother you both further for any recommedation for a pump which would suit the bath taps and shower combined. Access to the feed 22mm feed pipes is really easy so it should be a simple change.

I have no idea what kind of pressure to go for as I have no familiriarity of what 1bar or 5 bar feesl like. There are so many options its a bit confusing. Is this one suitable?

http://www.salamandershowerpumps.co.uk/salamander-pumps/products/salamander-rhp75-pump.html

I have a grohe 3000 http://www.plumbnation.co.uk/site/g...00-thermostatic-ev-mixer-shower-1-2---34181-/


Thanks