RPZ

What's an RPZ valve?

A reduced pressure zone valve or RPZ valve is a backflow prevention device used to protect the drinking water supply. Wherever a significant health hazard (fluid category 4) is identified in a plumbing system, backflow protection is required by law. One method to protect against this level of risk is to install an RPZ valve.

Key things to remember with an RPZ valve:

1. You must notify the water undertaker to gain consent to install the RPZ
2. The RPZ valve must be installed in line with the approved installation method (AIM)
3. The RPZ valve must be tested annually (as a minimum) by an approved tester

Why do you need to test your RPZ valve?

Much like the MOT on a car, an RPZ valve must be tested annually by law to ensure it is operating correctly. Remember, the valve is installed to prevent contamination of the drinking water supply, so it is vitally important that it works properly.

The test requires specialist equipment and can only be completed by an approved RPZ valve tester.

Approved RPZ Valve testers can be found on the WaterSafe website. 

Find an approved tester

When does an RPZ valve need testing?

When an RPZ valve is commissioned, Yorkshire Water will agree a test interval and test due date, typically twelve months after the initial commissioning. Compliance testing must be completed no later than the agreed due date.

For RPZ valves requiring annual testing:

• A compliance test must not be carried out earlier than 30 days before the test due date
• Earlier testing may be allowed in exceptional cases where agreed in advance
• Late testing is not acceptable and may result in enforcement action
• The test due date does not change following a late test.

Test date examples: 

Can you change your test due date? 

We understand that a test due date may not always be convenient or may not align with other RPZ valves on your site. In exceptional circumstances, and at our discretion, we may agree to an alternative date, provided the valve remains within its current compliance window.

To request a change, please email rpz@yorkshirewater.co.uk and include your reason for the request.

What happens if you fail to get your RPZ valve tested?

Yorkshire Water have a legal duty to enforcement of the water supply (water fittings) regulations 1999 and this includes ensuring all RPZ Valves comply with the approved installation method (AIM). In the event a RPZ valve is not tested as required, Yorkshire Water may issue an enforcement notice under Section 75 (1) of the Water Industry Act 1991. This notice gives Yorkshire Water statutory powers to visit your premises, carry out the test, and recover its reasonable expenses from you.

Can you remove an RPZ valve?

An RPZ valve may be removed, subject to approval, if it is no longer required. Examples include:·

• The appliance protected by the RPZ valve has been removed
• A replacement appliance includes built-in fluid category 4/5 (FC4/FC5) protection
• The process or appliance is now supplied from a FC4/FC5 storage cistern.

If you wish to discuss removal, please contact us at rpz@yorkshirewater.co.uk or complete an Application to Remove

Further information

For more information on RPZ valves please check out the FAQ page on Water Regs UK website.

RPZ installation and testing documents 

For approved testers, please download and complete the required documentation below and email to rpz@yorkshirewater.co.uk. 

RPZ AIM

RPZ Valve Application to Install/Relocate

Application to Remove

Commissioning Report Form

Combined Commissioning and Compliance Test Report Form

Compliance Test Report Form