Share optimized solutions, professional valve knowledge and industry news

What is a Thermostatic Mixing Valve (TMV)?


A thermostatic mixing valve (TMV) is a crucial device in modern plumbing systems, designed to precisely control the temperature of water delivered to taps, showers, and other outlets. This valve blends hot and cold water to a set temperature, ensuring consistent and safe water temperatures, preventing scalding.

How Does a TMV Work?

The core functionality of a TMV hinges on a temperature-sensitive element within the valve that adjusts the mix of hot and cold water based on the set temperature. This element expands and contracts with temperature changes, modulating the valve’s mechanism to allow more hot or cold water to achieve and maintain the desired temperature output, even when water pressure fluctuates.

Safety and Regulations

TMVs are essential for safety in both residential and commercial settings, especially in healthcare facilities where vulnerable groups such as the elderly or children are present. To enhance safety, TMVs are designed with fail-safe mechanisms that shut off the mixed water flow if the hot or cold supply fails, thus avoiding the risk of delivering water that is too hot or too cold.

These valves comply with international standards like BS EN 1111:1999 and BS EN 1287:1999, ensuring they meet stringent quality and safety requirements.

Benefits of TMVs

  1. Scald Prevention: TMVs maintain water at safe temperatures, significantly reducing the risk of scald injuries.
  2. Energy Efficiency: By efficiently managing water temperature, TMVs help conserve energy, reducing heating costs.
  3. Enhanced Comfort: They provide a consistent water temperature, improving user comfort in showers and baths.
  4. Regulatory Compliance: In many regions, installing TMVs is mandatory in certain buildings, such as schools and healthcare facilities, to meet safety regulations.

Installation Considerations

Installing a TMV requires careful consideration of water pressure, the temperatures of the incoming water supplies, and the specifics of the installation site. The valve should be accessible for maintenance and installed as close as possible to the point of use to minimize the lag time for temperature adjustment and the length of pipework where temperature can dissipate.


Regular maintenance is crucial for the effective operation of TMVs. It is recommended that TMVs are checked and serviced at least annually to ensure they function correctly and safely. This involves verifying the calibration of the valve to ensure it continues to control the temperature accurately, even with changes in water supply conditions or wear and tear of the valve components.


Thermostatic mixing valves represent a critical development in plumbing technology, offering enhanced safety, comfort, and compliance with health and safety standards. Their ability to precisely control water temperature not only safeguards against thermal shock and scalds but also contributes to the overall efficiency and sustainability of water heating systems. Whether in a domestic setting or a commercial environment, the benefits of installing TMVs are compelling and align well with modern demands for safety and energy efficiency.

Picture of
Hi, I’m Sophia Wang, the Marketing manager of, I’ve been working in this factory 8 years now, and the purpose of this article is to share with you the knowledge related to pressure control valves from a Chinese supplier’s perspective.

Get FREE 3D Design & Samples !!!

  • Get a FREE 3D design  about custom Pressure Reducing Valves!
  • Get FREE SAMPLES for Pressure regulator valve!!

Note: Your email information will be kept strictly confidential.