Hot water systems that are maintained infrequently or incorrectly can cause a multitude of problems. These problems range from higher risks of scalding through to legionella. TMV’s in the water system can help improve the safety of hot water systems.
Public health England reported more than 100 cases of legionnaires disease in 2020. Keeping the temperature of stored water above 60 degrees prevents the growth of legionella bacteria. However, this can increase the risk of scalding. is it time to improve your hot water system safety?
What are TMV’s?
TMV’s are thermostatic mixing valves. They use temperature-sensitive elements to mix hot and cold water to a temperature that safeguards against both legionella and scalding. Although TMV’s are not a legal requirement in existing bathrooms, fitting them will safeguard the end-user.
TMV’s are fitted to an outlet and mix water automatically, this is controlled by an internal thermostat that ensures the water is mixed to a safe temperature. Correctly installed TMV’s ensure that a predetermined temperature is maintained, this will remain unaffected even when other appliances are in use and the water pressure fluctuates. If either the hot-water or cold-water supply is cut off the mechanism will shut the valve off automatically.
Installation and maintenance of the TMV
Before installing the TMV’s inspect, clean, descale and disinfect the filters and strainers to ensure that any build-up of dirt is removed. In the commercial setting, TMV’s require periodic inspection, cleaning, and testing. To remain compliant with NHS DO8 standards the valves should be checked every 6-8 weeks. These checks should include:
- Thermal element endurance test
- A hot spike test.
- A response on adjustment check
- A fail-stop valve check.