Understanding and Choosing the Right Pressure Taps for Your Home Water System

Posted by ilker Duymaz on

water pressure guide

Choosing the right pressure taps for your water system is of paramount importance. If you install a tap that requires high pressure in a low-pressure system, it could lead to a reduced flow rate or subpar performance.

Not all taps or showers are suitable for every household

Some taps or showers function optimally even in low-pressure ('gravity') systems, while others necessitate a minimum water pressure (measured in 'Bar') to work correctly. Therefore, it's essential to understand the water pressure in your home and take this into account when selecting your bathroom fixtures.

Understanding Water Pressure

Water pressure denotes the force exerted by the water moving through your pipes. It's measured in bars, with 1 bar equating to the force required to elevate water up to a height of 10 metres. Every tap or shower has a specified minimum pressure rating, generally between 0.1 and 3 bar.

The Source of Water Pressure

Water enters your home via the cold mains under pressure, known as 'high pressure'. If you own a combi boiler, this device heats the water, maintaining most of its original pressure, thus ensuring good flow. If your home operates on a gravity system, the mains pressure dissipates, and your taps and showers receive pressure from the gravitational pull moving the water downwards from your water tank.

There are also other water systems apart from gravity and combi boiler systems. For instance, newer or larger houses often use an 'unvented', or 'megaflo' system. Here, the water is stored in a tank but in a pressurised environment, so it doesn't depend on gravity for motion.


Varieties of Central Heating Systems

The water pressure in your home and the type of tap and shower you can use largely hinge on the type of heating system installed.

Gravity Fed Heating Systems

A gravity system is a low-pressure system consisting of a cold water storage tank (typically situated in the loft) and a hot water cylinder. The pressure distributed throughout your home depends on the elevation of the cold storage tank relative to the tap locations in your house. Hence, in gravity systems, a 1 metre drop from the water tank usually corresponds to approximately 0.1 Bar of pressure.

Therefore, if your upstairs bathroom taps are around 2 metres below your tank, this results in a water pressure of 0.2 Bar, and if your kitchen taps are approximately 5 metres below your tank, they receive around 0.5 Bar of pressure.

water pressure guide

Tap & Shower Options:


If your home operates on a gravity system without a pump, it's likely you have 'low' water pressure, and should consider taps and showers with a 0.2 bar rating or less. Remember that even with suitable taps, the pressure generated has limits, so the water flow (litres per minute) is finite. If you're expecting a 'good' shower, you may be let down.


For a few hundred pounds, you could add a pump, expanding your choices when picking your taps.

Browse Low Pressure Taps Combi-Boiler

A combi boiler is usually installed at the point where the pressurised cold mains water enters your property, often in the kitchen. It controls both your hot and cold water supplies as well as your central heating, hence the name ‘combination’.

The combi boiler heats cold water directly from the mains supply as it's needed when the hot tap is switched on. As the water supply is from the mains and at mains pressure, your water will have high pressure and be suitable for a majority of high-pressure taps provided your combi boiler is fairly efficient. Pressures may differ between boilers, but the typical pressure expectation from a combi boiler is somewhere between 1 and 2 Bar.

Tap & Shower Options

If you have a combi boiler, especially a relatively recent one, it likely has a display showing the water pressure you're receiving. Generally, this is around 1-1.5 bar, although it can sometimes be higher. Most taps and showers can work with this level of pressure.


Unvented Water System

An unvented water system (also known as a Megaflo system) fills a primary cylinder with cold water directly from the mains. Unlike a traditional gravity system, an unvented system doesn't need additional storage tanks and instead offers a more straightforward solution.

The water in the main cylinder remains constantly pressurised due to the incoming mains water and is then heated indirectly from an external source like a boiler, solar panel, oil, or electricity.


If your home has an unvented water system, you have a wide range of options for taps, showers, and accessories including body jets, large rain heads, and simultaneous operation of 2 or 3 outlets.

Please remember that this is just a guide. Numerous other factors, such as the direction and curvature of the pipework or the size of the pipes, can influence water pressure.

If you're uncertain about your home's water pressure, it's best to consult your plumber before purchasing any fixtures. A plumber can use a pressure gauge tool to determine your home's exact water pressure, giving you a clearer idea of suitable taps.

For instance, if you install a high-pressure bath filler in a low-pressure system, it could take a long time to fill the bath, and as the water continually cools, you'd need to use more hot water to compensate. At Ultra Bathroom, all our bathroom taps have clearly labelled minimum pressures in the item specification tab.


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