Not all taps and showers are the same. Some are designed to work with lower water pressures, some with higher. It is important that you know which you will need for your particular installation so as to maximise water flow rates. To do this, first establish which system is used to deliver your hot and cold water:

Gravity feed — typical of a conventional boiler utilising a separate hot water cylinder for storage (maybe in an airing cupboard), with cold water supply tanks above (possibly within a roof space). The water pressure will be determined by the head of water, or distance from the tap or shower head to the base of the cold water supply tank above. The greater the height, the higher the pressure. Taps downstairs will therefore have greater pressure than those upstairs.

Combination boilers — are closed, pressurised systems, and a hot water tank is not normally used. Assuming they are supplied by average water pressure levels, they will usually provide 1.5 to 2.0 BAR of water pressure to the tap/shower head. If in doubt, your plumber can measure the pressure for you, preferably at the general peak use times of the day, where any reduction in mains water supply pressure will expose reductions in your combination boiler system pressure, giving you a worst-case scenario.

Ensuring sufficient supply pressures (and consequent water flow rates) is most critical with bath taps and bath mixer taps, as these often have to deliver the most water in one session. Showers and basin/bidet taps typically need to deliver less water continuously, so slightly reduced pressure and consequent flow rates are not as significant.

It is important to have reasonably balanced water pressure in both hot and cold supplies. This is especially true for mixer taps and valves, where an imbalanced supply will adversely affect the performance of the product.

The satisfactory operating pressures for our products are listed in the table below.
For extremely low water pressure systems
(where pressure is typically less than 1 BAR)
We have specially designed mixer taps in the Smart range which deliver acceptable flow rates even at very low pressures.