Safeguarding end users: delivering plumbing safety with water control valves

At the heart of any plumbing and heating system lies a fundamental need for safety, ensuring reliable water supplies that protect users and the broader supply network. When systems are designed, installed and maintained correctly, risks such as scalding and backflow prevention can be successfully mitigated against. 

Ensuring plumbing safety across every system, the Building Regulations provide clear guidance around key risks, such as scalding and backflow prevention, and the steps that are required to avoid these occurrences. In practice, this ensures users are protected at the point of use. 

Of course, not every building or project is the same, and plumbing safety requirements are different between domestic and commercial environments. In domestic setting, for example, Part G of the Building Regulations define the specific requirements that must be met when it comes to delivering water safety for users. 

In commercial settings, like schools and hospitals, safety is even more important. This is down to factors such as systems being larger, serving more users and, often, more vulnerable people – all of which mean there is a greater risk potential should safety not meet the standards. To ensure high levels of safety, healthcare settings are required to meet more strict standards, including the NHS D08 criteria for hot water in these environments. 

Every home relies on a safe water supply. Whether they’re apartments or larger family homes, kitchens, bathrooms and utility spaces are built around the safe, reliable and efficient supply of water. Plus, when you consider the average person uses up to 140 litres of water every day, they’re coming into regular contact with it – and every use highlights the need for safety. 

There are two key areas of concern in when it comes to protecting users in domestic environments – water temperature and water sanitation. 

Where water temperature is concerned, it is crucial for systems to feature the appropriate solutions – such as thermostatic mixing valves – for maintaining temperatures at a safe level consistently. Without specifiers and installers actively taking these steps, users are potentially left open to high temperatures and are at an increased risk of scalding whenever they turn on a tap, hop in the shower or run a bath. 

Backflow prevention is also a very real concern in these environments – classified under Fluid Category 2. As a result, systems need to be able to offer built-in protection against backflow and any resulting contamination. Not only does this protect users, but it also protects the system itself, ensuring potable water supplies remain fit for use. 

To achieve this, some of the key valves to include in domestic systems are: 

• Thermostatic Mixing Valves (TMVs) 

Designed to blend hot and cold water at the point of use, TMVs are recommended to be fitted ahead of every outlet – although they are only legally required ahead of baths in homes built or renovated since 2010. 

Having TMVs installed allows for hot water to be delivered at a set maximum temperature, significantly reducing the potential for scalding. This is achieved by the valve mixing hot and cold water immediately ahead of the outlet, and many TMVs feature shut-off technology to further enhance plumbing safety. In practice, this feature will shut-off supply to the outlet if the valve isn’t able to blend hot and cold water effectively – for example, if there is a failure with the cold water supply. 

In domestic settings, the Easifit TMV2/3 from Reliance Valves provides an ideal solution for delivering on plumbing safety. Its compact design means it takes up little space once installed beneath a basin or bath. The TMV is also fully compliant with British requirements, meeting WRAS and NSF TMV2 and TMV3 certification. 

• Check Valves 

Where a solution to backflow contamination risk is required, double check valves provide a double layer of protection. Featuring two valves in a single unit, they ensure a back-up should one valve fail to prevent the occurrence of backflow and contamination of the water supply. 

We know that backflow is caused by a sudden drop in pressure within a plumbing system, creating a vacuum effect which draws water the wrong way, potentially leading to contamination which compromises safety. Inside the double check valve is a check cartridge which, under normal operating conditions, is held closed by the system pressure. Should a vacuum occur, the cartridge opens to allow air to flow through and equalise the pressure to stabilise the system and restore plumbing safety. 

The Floguard Single and Double Check Valves in the Reliance Valves range offers a compact and lightweight solution for use in domestic plumbing systems and, ensuring compliance, is WRAS approved. 

In commercial systems, the risk to user – and public – safety largely stems from the same sources as in domestic settings, but on a much larger scale. 

Take hospitals, schools or care homes as an example where there is a much higher volume of outlets and users. Larger and more complex plumbing systems means a greater risk to people, the system and the potable water supply should plumbing safety be compromised. Users in commercial environments are often more vulnerable, too – whether they’re young children in schools, or patients in hospitals and care homes. 

Delivering on safety in these environments relies on the same technology – but it must be applied more broadly, meet specific regulatory requirements and be maintained more frequently. 

• Meeting regulatory requirements with TMV 

In certain settings, such as hospitals and care homes, meeting the requirements of the TMV3 scheme is essential in order to protect users at every outlet. As well as using valves that are able to operate within these requirements, the levels of maintenance are also more stringent, with servicing and testing required every six months. In commercial environments away from healthcare, the TMV2 scheme is generally adhered to, with lower test frequency and ongoing maintenance required – typically on an annual basis. Where risk is at its lowest, such as in domestic homes, Part G of the Building Regulations will be the most critical to follow, providing a baseline of safety without the need for regular ongoing maintenance. 

• TMVs must be TMV3-certified 

While domestic TMVs are only required to meet TMV2 standards, commercial buildings require TMV3 certification, providing certainty that the valves can stand up to the greater demands placed on them. As TMV3s are predominantly user 

Specification, installation, testing and maintenance requirements are defined within the NHS D08 specification, and TMVs must be installed ahead of every outlet and have a maximum hot water temperature between 38°C to 44°C. This range allows for different areas – whether catering to the requirements of staff, visitors or patients – to meet specific needs 

TMV3s are predominantly used in healthcare settings whilst TMV2s are used in domestic dwellings. However, they also cover non-healthcare commercial applications like service stations, gyms, swimming pools and others. The key difference between the valves is that TMV2 valves are able to group mix, meaning this valve can serve multiple taps and showers. This is perfect for a rugby or football club, allowing a constant flow of safe water pressure and temperature conditions.  

Whilst TMV3 applications are designed to be used as one valve per tap, another difference between the two is the testing frequency of both types of valves. Testing required for TMV2s need to be completed annually whereas TMV3s require more frequent testing due to the high volume of water needed, and they are used more regularly.  

The Reliance Valves Heatguard TMV3-8 provides the ideal solution for these settings, ensuring the effective mixing and delivery of hot water to prevent accidental scalding. The valve also shuts-off immediately should the cold water supply fail, preventing unsafe temperatures from reaching the outlet, and is also NSF approved for added peace of mind when specifying for healthcare environments. 

• Reduce Pressure Zone (RPZ) Valves  

RPZs should also be installed in commercial buildings to prevent the occurrence of backflow. Hospitals are Fluid Category 4 environments, so these valves ensure the water supply remains clean, as well as preventing backflow from contaminating the supply. 

The Commercial BA RPZ Valve from Reliance Valves has been developed to respond specifically to the demands of Fluid Category 4 buildings, preventing contamination, back pressure or back siphonage from occurring and compromising plumbing safety. As well as being compliant with the relevant standards – including BS EN1717 and Regulation 4 cold water approved – the valve’s design supports straightforward servicing and maintenance with an easily-accessible one-piece cartridge. To ensure ongoing compliance, every RPZ must be tested annually by an approved tester, as well as upon initial commissioning. 

Water safety is crucial in every setting, be it domestic or commercial, and valves are key to designing systems that put user safety at their core. 

Reliance Valves is a leading manufacturer of water control valves. Backed by 75 years of experience and a team of dedicated experts, specifiers can rely on the support they need to get plumbing safety specification right every time.