TMVs: all you need to know about compliance

Thermostatic Mixing Valves (TMVs) have a prominent role to play in plumbing systems across domestic, commercial and healthcare environments. By blending hot and cold water at the point of use, TMVs underpin safety efforts by ensuring hot water is delivered at suitable temperatures for the users served by the system.

In newly constructed domestic and commercial settings, TMVs have been a legal requirement for more than a decade. In homes, they can be fitted behind baths, showers and taps to protect users and they are widely used in healthcare and commercial settings – including hospitals, care homes and schools – to minimise the risk of scalding and ultimately protect vulnerable people.

In this blog, we’ll recap the basics of TMVs including how they are categorised and their general uses, before delving into the specifics behind the testing and commissioning which ensures your TMVs compliance with industry standards.

Generally categorised into two application types - TMV2 and TMV3 – these essential safety valves are designed to perform to different temperature requirements, ensuring their suitability across a range of applications.

Domestic and commercial applications require TMV2-certified valves as they can maintain safe and stable temperatures up to 46°C and will shut-off in the event of a cold water failure. The TMV2 scheme has been part of the Building Regulations in Britain for domestic buildings since 2010, requiring baths in new build homes and existing homes undergoing bathroom renovations to have TMVs installed.

TMV3-certified valves are most widely used in healthcare buildings, where safety valves are individually specified to ensure they meet the specific requirements of risk assessments. In NHS settings in particular, the specification of TMV3s should also align with the requirements set out in the NHS D08 Specification.

Whether designed for TMV2 or TMV3 applications, each solution features the correct markings to make them easily identifiable, and are required to be supplied with relevant maintenance documentation to ensure their continued TMVs compliance post-installation. This is because TMVs should be tested regularly to ensure they remain in good working order.

To perform as required every time a tap is turned on, each TMV has a temperature controlling element at its core. This allows the valve to respond accordingly to keep temperatures safe and stable, maintaining the correct balance of hot and cold water passing through the valve to be mixed.

The ability of TMVs to deliver this important safety role consistently is bedded in quality. The high-quality construction of TMVs ensures they can stand up to the demand of even the busiest environments and is something which is reflected in the accreditations carried by TMVs.

As a leading manufacturer of water control valves for plumbing and heating applications, Reliance Valves ensures every TMV meets all of the relevant test criteria for their intended applications. As well as giving specifiers and installers confidence in every product, TMV compliance helps to simplify specification by removing the complexity from product selection.

Where TMVs are concerned, a key certification comes from NSF – an independent testing body dedicated to the rigorous testing of components to ensure they meet the standards required of their applications.

Through a rigorous testing procedure carried out on a sample selection of TMVs, the NSF certifies products for use in TMV2 and TMV3 categories. Each test puts the critical functions of TMVs through their paces, including their ability to mix water effectively, withstand anticipated system pressures, maintain suitable water temperatures and shut-off when conditions mean they can’t operate safety.

As well as being WRAS-approved, all TMVs within the Reliance Valves range are NSF certified. This includes the TMV2/3-certified Ausimix Compact TMV, Easifit TMV and Heatguard Dual TMV and TMV3-certified Heatguard Style TMV and Heatguard TMV.

With the right solutions, backed by the relevant testing standards, specifiers and installers can be confident that their projects are delivering the relevant levels of safety.