To ensure you achieve the best possible performance from your chosen product, you need to be able to identify the type of boiler you have and therefore your water pressure.

The following information provides a general overview on water pressures and a guide to ensure you choose the right product for you and your home.

What is water pressure and why is it important?

This is the measurement of how fast water flows through your pipes and taps. Your water pressure is determined by your boiler/water tank.

Which type of boiler do I have?

3 types of boiler systems exist: gravity-fed, combi boiler and unvented - and each can influence water pressure differently.

 

Gravity-Fed: 

Found in older UK housing with the following features typically:

 

• Typically features a cold-water tank in the loft and a hot water cylinder elsewhere in the house.
• Hot and cold pressures are typically unbalanced (the cold-water pressure is higher than the hot). Cold water pressure is as per incoming mains.
• Hot water pressure (head pressure) is distance ‘a’ in metres divided by 10. For examples if 'a' is 1 metre then the hot water pressure is approximately 0.1 bar.
• This type of system is generally considered as low pressure.

 

Gravity-Fed (pumped):

Found in older UK housing that has been modernised.

 

• Hot and cold pressures are typically unbalanced (depending on the cold mains pressure and the rating of the hot water pump). Cold water pressure is as per incoming mains.
• Hot water pressure is as per the pump rating.
• This type of system is generally considered as high pressure.

Combi Boiler: 

Found in newer UK housing.

 

• Generally found wall-mounted in the kitchen.
• Cold water pressure is as per the incoming mains.
• Hot water pressure is as per incoming mains but generally reduced slightly due to pressure reducing valves, filters and flow limiters.
• This type of system is generally considered as medium - high pressure.

Unvented: 

In UK housing with a hot water tank but no cold tank.

 

 

• The cylinder(s) can be located anywhere in the house.
• Hot and cold pressures are typically balanced.
• Hot and cold-water pressure is typically 3 bar (as shown), otherwise the hot and cold pressure will be approximately the same as the incoming mains cold pressure.
• This type of system is generally considered as high pressure.

If you have low water pressure you should take care to choose a product that is suitable, otherwise you might find that the flow rate is poor, and it will be difficult to achieve a mixed temperature.

If you have high water pressure you can choose any product with the same or lower pressure requirement.

As a general guide only, when connecting multiple products you should work to the product with the highest pressure rating.

In the product details and specification section on each product page you will find both the ‘pressure type’ which will be listed as low, medium or high and the ‘minimum bar pressure’ requirement of the tap via an icon next to the product image(s).

Please note all products marked as low pressure and medium pressure are also suitable for high pressure water systems.

How is water pressure measured?

Water pressure is measured in ‘bar’. Usually anything 0.3 bar or below requires a low water pressure tap or shower, and anything at 1.0 bar or above requires a high-water pressure tap or shower.

 

How to check your water pressure

Your local water supplier or plumber will be able to advise. Plumbers use pressure gauge tools (or you can purchase one which you can fix to the tap yourself). Or you can calculate the approximate value by measuring the drop between your water tank and the tap in metres.

Calculation: One metre = 0.1 bar

Water systems which operate at 1.0 bar pressure (10 m of drop) or greater are considered high pressure systems. Those with a pressure less than 1.0 bar are considered low pressure.

 

How do I pick suitable products?

Ensure you check that the minimum water pressure required is the same or lower than your home’s water pressure.

If you have low water pressure, look for kitchen taps that are labelled as suitable for high and low water pressure systems. Check that the minimum water pressure is the same as, or lower than your water pressure.

If you have high water pressure, you can choose from taps which are labelled as suitable for high and low water pressure systems, or high pressure only.