Information on Thermostatic Mixing Valves

TMVs accurately control water temperatures for hand-washing, bathing, showering and bidets. They are designed to maintain the desired water temperature, even when the incoming water pressures or flow rates change.


TMVs provide two important solutions:
  • Allow water to be stored and circulated at temperatures that combat Legionella bacteria – while ensuring water is delivered at a safe temperature
  • Prevent scalding injuries – these can be fatal, especially to vulnerable groups such as the young and the elderly, and sadly 20 people died as a result of contact with hot water across England and Wales in 2011. Failing to fit or removing a TMV will increase the risk of scalding.

The benefits of TMVs are endorsed in many official safety regulations and guides:
  • Building Regulations Part G
  • Department of Health HTM 04-01
  • HSE ACoP L8 (Control of Legionella)
  • HSE HSG220 (Health and safety in care homes)
  • Department for Education BB87
  • NHS list of preventable ‘Never Events’
  • BRE IP 14/03
Product quality is ensured by compliance with:
  • approval schemes TMV2 and TMV3 (operated by BuildCert and based on European standards)


  • WRAS (Water Regulations Advisory Scheme)
  • D08 (for valves used in NHS facilities)
The TMVA helped to develop these important regulations, guides and standards by engaging fully with public bodies and by publishing its own Code of Best Practice. The Water Safety & Hygiene website contains detailed FAQs and the group provides a reliable service of answering technical queries. BEAMA will continue its work to
promote correct design, installation, use and maintenance of TMVs.
Progressing to the Water Safety & Hygiene group means also using members’ expertise around the products on pages 3 and 4, allowing the group to promote best
practice that has a larger impact on improving the safety, hygiene and economy of the whole system. BEAMA believes issues in water systems can almost never be solved by
addressing just one part, be it products, setup or usage – the infamous silver bullet does not exist.