Understanding water pressure

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Water pressure is a measure of the force that gets the water through our mains and into your pipes.

It is measured in 'bars' - one bar is the force needed to raise water to a height of 10 metres. We need pressure to push water through our pipes and into homes and businesses, whether they are in valleys, higher and hillier areas, or are raised like some flats and apartments.

How much pressure should I have?

The water industry regulator Ofwat under the guaranteed standards scheme (GSS) sets out that water companies shall maintain a minimum pressure of water in the communication pipe serving the premises supplied with water of seven metres static head.

The amount of pressure at your tap depends on how high our service reservoir or water tower is above your home, or on how much water is being used by other customers.

Water pressure can vary at different times of the day. Pressure is normally higher late at night when very little water is being taken from our network and most people's taps are turned off. In the morning when people are taking a bath or shower, or watering their garden on a hot evening, there is a bigger demand for water which can cause low pressures.

The pressure also varies with the ground level. In hilly areas, the pressure will usually be high in the valleys, which are a long way below our reservoirs, and lower on the hilltops.

It is possible to make changes to your internal plumbing to increase your water pressure - for example by ensuring your stop tap is fully open, or checking that any systems that depend on the pressure of water reaching the property are set to the statutory minimum level of 1 bar/10 metres head.

Experiencing low pressure?

If your water pressure is too low, you should check that there is no problem with the plumbing in your property, such as a partially closed internal stop tap (if fitted) or a leak.

If you cannot find a problem, please contact us. We can take pressure and flow measurements and determine whether the problem lies in pipes belonging to us or you.

More information on what to do if you have low water pressure can be found by watching our helpful video guide.

Watch our how to guide

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