You can do this by completing a notification form and emailing it to us at Regulation5.Notification@wessexwater.co.uk or sending it by post to Wessex Water, Regulation 5, Developer Services, Claverton Down, Claverton, Bath BA2 7WW.

If we do not receive a passed test certificate from an approved tester within 14 working days of the due date of the test, we will attempt to contact the premises owner or person responsible for the RPZ valve.

Our last available resort will be to switch off the water supply to the premises until a passed RPZ test certificate has been received.

Before installing an RPZ valve in premises already connected to the mains water supply, you must notify us first. This applies to all new RPZ valves, even if there are others already installed.

All test certificates must be emailed directly to us at RPZ@wessexwater.co.uk within 10 working days of the test being carried out.

Series 009-AUS reduced pressure zone backflow preventer devices are designed to protect potable water supplies in accordance with national plumbing codes and water authority requirements. This series can be used in a variety of installations, including the prevention of health hazard cross-connections in piping systems or for containment at the service line entrance. This series features two in-line, independent check valves, captured springs and replaceable check seats with an intermediate relief valve. Its compact modular design facilitates easy maintenance and assembly access.

RPZ valves must be tested at a minimum of every 12 months unless a more regular frequency is required by the water undertaker.

Once approval has been granted for the installation of the valve, it must be installed by an approved, registered contractor and in accordance with the Water Undertaker's Approved Installation Method (AIM) document.

Series 009-AUS reduced pressure zone backflow preventer devices are designed to protect potable water supplies in accordance with national plumbing codes and water authority requirements. This series can be used in a variety of installations, including the prevention of health hazard cross-connections in piping systems or for containment at the service line entrance. This series features two in-line, independent check valves, captured springs and replaceable check seats with an intermediate relief valve. Its compact modular design facilitates easy maintenance and assembly access.

Wessex Water Services Ltd, Registered in England No. 2366648 Registered Office: Operations Centre , Claverton Down Road, Claverton Down, Bath BA2 7WW.

If we do not receive any response a regulations officer will be arranged to visit the premises and carry out an inspection to assess the risk. The visit will also involve agreeing on a mutual resolution to the problem where possible.

For product-specific approval information, please refer to the product’s specification sheet or contact us. For general information regarding any approval certification partners identified in the specification sheet, please visit our certification partners’ websites:

If you are experiencing an issue with our services or require additional support, see our advice and discover how we can help.

A letter advising the test is overdue and must be carried out at the earliest opportunity will also be sent to the property.

Our regulations officers may require a site visit to inspect the RPZ to confirm it has been installed in accordance with the AIM document.

All test failures must be reported to us within at least 24 hours. Please email us at RPZ@wessexwater.co.uk and include details of the failure and the planned actions and associated timescales to resolve the issue.

We have 10 working days from the receipt of a formal notification to grant consent for the installation of the RPZ valve.

If the risk is considered to be significant due to the nature of the water use at the premises, a regulation officer will be arranged to visit and assess the risk. As a last resort, the water supply to the premises may be switched off until the issue with the RPZ valve can be resolved.

Reduced Pressure Zone (RPZ) valves are installed to prevent the backflow of fluids that represent a significant health hazard (fluid category 4).

The RPZ valve and fitting(s) it supplies must remain isolated until the RPZ valve can be repaired or replaced. The supply to the valve must not be reinstated until a satisfactory test pass is achieved.