Water pressure

What is water pressure?

Pressure is the force that pushes water through pipes. Water pressure determines the flow of water from the tap. The amount of pressure at your tap can depend on how high the service reservoir or water tower is above your home, or on how much water other customers are using. The height of your property can also affect your water pressure – properties at the top of a hill may receive lower pressure than properties which are at the bottom of the hill. You should not notice any difference in your water pressure after having a water meter installed.

Low pressure can reduce water flow to a trickle and it will take a long time to fill a kettle or a cistern.  Some modern heating appliances and showers will not work below certain pressure levels. You should seek your water company’s advice before installing this type of equipment to check whether the pressure in your water company’s area is sufficient for these systems to operate efficiently.

Low pressure can have a number of causes. For example, when demand for water is high (such as in the morning or early evenings) pressure can be lower than during the rest of the day. There can also be problems during dry spells when people use hosepipes or sprinklers to water their gardens.

Other causes of low pressure can include:

  • inadequate pumping facilities
  • water mains that are too small
  • reduced pressure from the water main as a result of leakage, equipment failures or blocked service pipes

These are the companies’ responsibility.

Pressure that is too high can damage plumbing fixtures, which may cause flooding. The main causes of high water pressure are listed below.

  • Trapped air in your water pipes, which can temporarily increase water pressure. Run your taps for a few minutes to release this air.
  • Re-configuring the water supply network when water is moved round to wherever it is needed, sometimes changing the supply route. Normal supply will be returned very quickly in most cases.
  • You’ve just moved to the area if you are new to the area, your water pressure may feel higher than you were previously used to.

What should I do if I have a problem with water 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, contact your water company. They can take pressure and flow measurements and determine whether the problem lies in the company’s or your pipes.

Water companies should make sure that high water pressure does not cause damage to a customer’s property if the customer’s fittings meet normal standards. If you have a problem with water pressure, speak to your water company first.

If you are not satisfied with the company’s response, you can contact the Consumer Council for Water (CCWater) for advice in pursuing the matter.

What are the official standards for water pressure?

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.

What else can affect your water pressure?

Some modern heating appliances and showers will not work below certain pressure levels. You should seek your water company’s advice before installing this type of equipment to check whether the pressure in your water company’s area is sufficient for these systems to operate efficiently.

The amount of pressure at your tap can depend on how high the service reservoir or water tower is above your home, or on how much water other customers are using. The height of your property can also affect your water pressure – properties at the top of a hill may receive lower pressure than properties which are at the bottom of the hill.

You should not notice any difference in your water pressure after having a water meter installed.

What action can companies take to improve pressure?

Companies can renovate the water main by scraping away any corrosion and putting in a new lining. They can also replace the main with a larger one or install pumps to boost the pressure.