Understanding Mains Water Pressure in Your Home

Mains water pressure is the force water is delivered into your home.

It’s measured in bar or psi (pounds per square inch). For example, 1.0 bar equals 14.5psi. One bar of water pressure is needed to raise water 10 metres high. This is often why flats and high-rise buildings require greater mains water pressure than other homes, as the water has further to travel.

What is the Normal Mains Water Pressure in the UK?

The amount of water pressure in your home will vary depending on a number of factors, including the time of the day and the ground level of your property. However, while these factors play a part, your water authority is required to supply a minimum of 0.7 bar of pressure.

What Affects Water Pressure?

Water pressure is important, as it is the force that pushes water through your home’s pipes. As a result, your home’s water pressure determines the water flow in your property — the higher the water pressure, the more powerful the water flow and vice versa.

The performance of any plumbed-in appliance, like a shower or toilet, can be affected by your water pressure or water flow. Some appliances such as an electric shower may not operate at all if the water pressure is too low.

A number of factors can affect water pressure. Some are found externally, like the supply from your water authority or leaks in the pipes under the road. You can find out who is responsible for your mains water pressure and what to do if you think you have a problem in our blog post.

Other impacting factors are found inside your home, like the size and length of internal pipework. For example, if the water has to travel a long distance through a pipe, your water pressure can drop. Another internal factor is the sheer amount of regular water usage.

Often, water pressure issues are identified at busy times of the day when water is being used by the shower, the tap and/or the toilet. At these times, the water flow is being split between each outlet, giving a poor performance. The more taps and showers being used at any one time, the more the pressure at each one falls.

Salamander Pumps has a range of solutions that can help deliver the pressure and flow you want, when you want it.

How Can I Check my Mains Water Flow?

You can test your water flow with a weir cup.

• Place a 1L  measuring cup under the shower or tap.
• Turn the problem tap or shower on full.
• Time how long it takes to fill the cup.
• If it takes more than 6 seconds to fill the cup, then you have low water pressure and flow.

You can also use our interactive flow calculator to work out the flow rate of a single outlet.

Salamander Pumps provides a solution to low hot and cold mains water pressure and flow.