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The challenges posed by low or high water pressure include impacts on system performance and longevity. Jerry Whiteley from the CIPHE discusses some of the potential issues and outlines what installers can do to overcome them.
Water pressure is required to be between a minimum of 0.7 to a maximum of 1.5 bar according to the service standard set out by the Water Services Regulation Authority (Ofwat). Therefore, low-pressure is characterised as a water system which falls below 1 bar, while anything above this is considered high-pressure. There are a number of reasons that pressure differs, but avoiding extremes in either too high or too low water pressure should be the goal.
High or low?
The cause of low water pressure in some cases can be due to area supply issues, such as a burst pipe or emergency repairs. If a property previously had no issues with water pressure and suddenly has a drop in pressure, then it is worth checking with the local water supplier first.
On the other hand, issues of low pressure may be a longer-term problem. If so, it may be that poor system design, incorrect diameter of the pipes, or even factors that are geographical or down to the housing type are affecting the water pressure. Older properties had a cistern-fed cold-water system, normally feeding the bathrooms, and these have larger diameter pipes for low pressure and flow.
Poor system design
Multiple storey properties in extreme cases can have systems that are unable to cope with the height of the building, if there is insufficient mains water pressure. In these scenarios, the top floors of the property can have low pressure or sometimes do not have a water supply at all. In regions with hilly terrain or areas that are more built-up, devices may need to be used to help improve the pressure.
It isn’t just low pressure that can be an issue however; high pressure can be equally as problematic. An indicator that water pressure is too high is noise within the pipework, which is caused by the water moving too quickly through the pipes. Not only is the noise undesirable, but high water pressure can increase wear and tear within the pipework. This can erode components, shortening the lifespan of plumbing fixtures and increasing the likelihood of costly leaks and pipe bursts.
Finding a solution
Resolving water pressure issues, whether too high or too low, is necessary. The first step is to ensure the water pressure is measured to obtain an accurate reading of the supply to the home. Before attempting to resolve pressure concerns and before any installation, the local water supply must also be checked.
The installation of a booster pump is often a straightforward solution for low pressure scenarios, as it increases water pressure by forcing the water to flow through the pipes at a faster rate. It is worth keeping in mind that water authorities limit this to 12 litres per minute, anything more and you must notify them beforehand.
Alternatively, an accumulator tank which stores cold water can be installed. An accumulator gathers water during low demand periods, for example overnight, and holds the volume of water under boosted pressure until it is required.
Generally, high-pressure properties are easier to solve when compared with the low-pressure counterpart. A pressure reducing valve installed on the main water supply pipe, for example, can help to regulate the water pressure as desired.
Don’t get caught out
In some instances, it may be necessary to convert a system from low pressure to high pressure. A common misjudgement that installers make is forgetting that the pipework is designed for low pressure, larger diameters and fitments, such as a shower. Connecting to an existing low pressure system is likely to result in poor water supply and poor quality, leading to a system design rethink. It is important to be aware that changing to higher pressure might identify weak joints and cause water damage. As such, systems must be tested in line with Water Regulations as it is the installer’s responsibility should a leak occur.
With installers often being the first port of call when and if homeowners experience water pressure issues, it is critical that plumbing and heating engineers are qualified, competent and able to resolve any problems confidently. The CIPHE can offer its members information and assistance across an array of plumbing and heating topics to support installers with queries surrounding technical issues, including water pressure.
For more information about the CIPHE, or to become a member, please contact the team via email: firstname.lastname@example.org or call 01708 472791