Modern Building Services

PIPED SERVICES, PUMPS &WATER A s plumbing and heating installers, we’re all aware of the dangers of Legionella, and the need to maintain water temperatures around 60-70°C in order to kill it off. While this solves the bacterial health risk, it also gives rise to another hazard – scalding. Burns caused by hot water from taps is rising steadily according to NHS data, and bath water scalds are rated as one of the most painful experiences that can be endured. Although these cylinders have fail-safe mechanisms including expansion vessels, thermal valves and pressure relief valves, they’re still subject to poor installation, maintenance and potential component failure. Moreover, while these protect the cylinder, they can’t prevent the water heating to dangerous temperatures long before the safety devices kick-in. Hot water splash back could potentially cause serious scalding injuries in less than three seconds. There are two effective solutions to this problem: tempering valves and thermostatic mixing valves (TMVs), both essential factors in safe hot water systems. Thermostatic mixing valves – a certified solution TMVs use an internal thermostat to automatically achieve and maintain safe water temperatures, typically around 48°C. In the event of hot or cold-water failure, they quickly shut down. There are two TMV schemes available. TMV2 which is designed for domestic, commercial and public FEATURE PIPED SERVICES, PUMPS &WATER 10 MODERN BUILDING SERVICES OCTOBER 2021 Incidents of scalding caused by hot water are on the rise, but there are easy ways to minimise this risk, including tempering valves and thermostatic mixing valves. Here, Richard Bateman , Product Marketing Manager at RWC UK, looks at the issues and the solutions, giving tips about correct installation and maintenance. Burning issues – the importance of safety valves in hot water systems