RPZ Valve Testing & Certification

RPZ valve testing and certification services

Pipe Dreams Plumbing and Heating offers a full RPZ valve service from installation, to testing, to yearly maintenance contracts. We can also provide a repair service for all types of RPZ valves, or source new ones for you if required.

We have WRAS accreditation for testing any make, model and size of RPZ valve and can produce the required paperwork and test certificates for your water supplier.

Fair prices

We charge £110 + VAT for the testing & annual certification of each RPZ valve.  Notifying your water supplier with the relevant certification is included in this price.

If you have a number of valves that require testing at one location or at a number of locations that are close to each other, we’ll happily discuss offering you our day rate of £440 + VAT if that works as a more reasonable option for you.

Covering the whole of the South East

As this is a relatively niche service, we’ll travel well outside of our normal Woking radius, but please note that we charge travel time at £78 + VAT for each hour of travel.

Contact us for a quote

We can provide you with a fixed quote that’s tailored to your requirements – just send us an email at web@pdph.co.uk or give us a call on 0800 690 6400.


Pipe Dreams RPZ valve testers


What is a Reduced Pressure Zone (RPZ) valve?

A RPZ valve is a unit consisting of two spring loaded check valves and a relief valve positioned to create a reduced pressure zone between the water source and the source of potential contamination.

RPZ valves are an approved method of preventing backflow and backsiphonage for fluid categories up to and including Category 4. For further information on fluid categories and backflow prevention please see our Water Regulations page.

They are often a preferred method of backflow prevention as they require less pipework modification and have a smaller space requirement than alternative methods such as break tanks.

How often do I need to have my RPZ valves serviced?

You are legally required to have your RPZ valve tested by an approved tester at least once every 12 months. Testing can be completed up to 30 days before your current certificate expires (similar to your car’s MOT).

When does my water supplier need to be notified?

Your water supplier requires any RPZ installation to be notified at least 10 working days before work commences. They also require notification of any test or maintenance performed or any change in location or fluid category.

How much does an RPZ valve installation cost?

The cost varies greatly depending upon the valve size, surrounding pipework and location. Please contact us for a quote for your requirements.

How long does it take to test a RPZ valve?

On average it takes around 30 minutes to test and certificate a RPZ valve. The water supply to the area will be interrupted for around 15 minutes.

What size RPZ valves can be tested?

We are qualified to test and install any size RPZ valve attached to any type of installation.

Can you supply RPZ valves?

Yes, we can supply direct replacements and genuine parts for your current valves. We also hold a number of new valves in stock in common sizes.

What happens if my RPZ valve fails the test?

All RPZ valves are designed to be repairable by means of replacement check/relief valves. We are fully trained and qualified to be able to carry out these repairs.

Why is my RPZ valve leaking?

If your valve is discharging water it may be a sign that there are either pressure variations on the incoming water supply and consequently the valve is functioning as it should, or that the valve is in need of servicing.