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Regulations and plumbing

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The Water Supply (Water Fittings) Regulations 1999 set out the installation requirements for plumbing systems. It works the same way as building regulations set out the requirements for buildings.

There’s been a long history in regulating plumbing systems in homes and businesses in the UK which is done to protect public health by safeguarding drinking water through the use of water company's Water Supply Byelaws.

The Water Supply (Water Fittings) Regulations 1999, prevent inefficient use of water, the waste, misuse, undue consumption, incorrect measurement of it and, most importantly, to prevent contamination of drinking water supplies.

These regulations are national requirements for the design, installation and maintenance of plumbing systems, water fittings and water-using appliances and supersede the previous Water Supply Byelaws that were written by each water company.

The Water Regulations Advisory Service (WRAS) provide national guidance on the regulations for water companies and their customers. Water Companies are responsible for the enforcement of the Regulations within their water supply areas. You can see a copy of our enforcement policy which helps us meet our legal obligations below.


Water Supply (Water Fittings) Regulations 1999

Where do they apply?

Since 1 July 1999 in England and Wales, all plumbing systems, water fittings and equipment supplied, or to be supplied, with water from the public water supply come under these regulations. This applies to systems in all types of premises including properties that use a private water supply and have a mains backup provided by water companies. The regulations apply from the point where water enters the property's underground service pipe to the point the water is used.

These regulations do not apply where a property uses a private water supply and doesn't have a supply of water from a water company. However, it is good plumbing practice to follow the requirements of the Regulations.

Who has to comply?

A legal duty is placed on all users, owners or occupiers and anyone who installs plumbing systems or water fittings to ensure they are installed and used in accordance with these regulations. Advanced notice must be given of proposed installations in most cases, so architects, building developers and plumbers have to follow the regulations on behalf of future owners or occupiers.

The application of the regulations cannot be back-dated. Any plumbing system or water fitting which was installed lawfully under the Water Supply Byelaws before the regulations came into force can still be used, even if its installation would not now be permitted by these regulations.

What are approved plumbers?

The regulations introduced the concept of Approved Contractors, more commonly known as Approved Plumbers. This is to identify qualified plumbers who are competent in the regulations. Approved Plumber status carries certain statutory responsibilities which benefit plumbers and their customers. These Approved Plumbers will certify the installation or maintenance work they have carried out complies with the regulations by issuing a certificate of compliance. If breaches of regulations are then found in the certified work, the legal responsibility falls upon the Approved Plumber and not on the owner or occupier.

The WaterSafe scheme aim is to raise plumbing standards by helping customers find the nearest qualifies plumbing and heating professionals. The scheme brings together thousands of qualified contractors employed by plumbing businesses and are members of one of the seven existing Approved Contractors’ Schemes running across the UK.
Search on the WaterSafe website to find an approved plumber in your area.


How do I comply with the regulations?

If you are a plumber/contractor or carrying out work,  you should obtain a set of the regulations, amendments and the guidance documents from HMSO or a Water Regulations Guide from WRAS and make sure that you carry out work according to these regulations. 

You should also consider applying to join Watersafe (the national register for approved plumbing businesses in the UK) and Anglian Water’s Approved Plumber scheme

If you are having work carried out on your behalf, you should make sure that the person or company you employ is aware of the regulations and any plumbing work you have done is carried out in accordance with them. You can find a list of approved plumbing businesses on the WaterSafe website.

Plumbing fittings

It is not illegal to sell unsuitable fittings and appliances but to install one would be illegal, so check suitability before purchase. The regulations detail standards for suitability and the Water Fittings and Materials Directory, published by the WRAS, gives up-to-date details of a wide range of items which have been tested and proved to comply, when installed correctly. 

Double check valves (DCVs) on household appliances

We have some important information in relation to double check valves (DCV) for internal domestic appliances such as dishwashers and washing machines, to share with you.

In April 2017, the Water Regulations Advisory Scheme (WRAS) released an amendment in relation to installation requirements under the Water Supply (Water Fittings) Regulations 1999 in England and Wales which now means these appliances will need an additional DCV installed at the point of connection between the water supply and the appliance.

IRN 160:
“A compliant double check valve or some other no less effective device providing backflow prevention protection to at least fluid category three shall be fitted at the point of connection(s) between the water supply and the fitting or appliance.Where the double check valve is for use with products that incorporate water injected with CO2 gas all metal parts in contact with the water passing through it must be constructed from chrome nickel stainless steel.”

IRN 360
“Domestic unvented primary circuits may be filled or replenished by means of a temporary connection between the primary circuit and the supply pipe. An ‘Approved’ double check valve shall be installed at the point of connection to the supply pipe. A permanent connection between the primary circuit and the supply pipe may be made via a CA backflow prevention device or some other no less effective backflow prevention device.”

Historically, an assumption was made that all domestic appliances were fitted with double check valves and internal inspections would have passed.

Our Customer Services Representative team will now fail all domestic internal inspections where appliances such as washing machines, washer-dryers and dishwashers where the fitting is not present.

If you have any questions in relation to this subject, please refer to our helpful guide ‘Water Regulations for Domestic Properties’.


How are the regulations enforced?

The Government requires water suppliers to enforce the regulations within their area of supply as with the previous Water Supply Byelaws. 

Anglian Water will undertake inspections of new and existing installations to check that the regulations are being met,and where... 

  • breaches of the regulations are found, we'll require that they are remedied as soon as practicable. 
  • breaches pose a risk to health, the water supply to the premises may be disconnected immediately to protect the health of occupants or others fed from the same public supply. The Government has deemed the risk such, that it is a criminal offence to breach the regulations and offenders may face prosecution.

Where can I find the regulations and further advice?

The regulations (SI 1999 No. 1148 and No. 1506) and their schedules are available online and can be purchased from HMSO. In addition the Government's guidance document relating to the schedules is also available online. The text of all these documents is included along with detailed water industry guidance and interpretation in the Water Regulations Guide which can be purchased directly from WRAS.

Anglian Water can't provide a design service for installations but we'll try to answer individual queries from customers, designers, builders and installers about the interpretation of the regulations. WRAS can also provide interpretation advice. 

We can provide copies of the regulations upon request. For more information contact Anglian Water

The Water Supply (Water Fittings) Regulations 1999

SI 1999 No1148

SI 1999 No1506 (amendment)

Government's Guidance Document

Water Regulations Guide and Water Fittings and Materials Directory

Water Regulations Advisory Scheme (WRAS)
Unit 13
Willow Road
Industrial Estate
NP11 3EH

Tel: 0333 207 9030

Where can I find information for landlords and households?

Following a recent incident, the Health and Safety Executive identified that poor or incorrect installation of cold water storage cisterns can put occupiers at risk if a fault occurs in the heating system.

More information is available on our landlords page regarding advice issued by HSE and the Water Regulations Advisory Service.

Our water regulations enforcement policy

Does your property comply with the water fittings regulations?

Further water regulations information

Find out more about water regulations, including greywater reuse and rainwater harvesting.


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