Thermostatic Mixing Valves (TMVs):
Complete Guide
What is a Thermostatic Mixing Valve (TMVs)?
A thermostatic mixing valve (TMV) is a valve that blends hot and cold water to ensure a nearly constant output temperature, such as for safe shower and bath temperatures to prevent scalding.
How does a Thermostatic Mixing Valve work (TMV)?
Thermostatic Mixing Valves (TMVs) work by automatically blending hot and cold water to deliver water at a safe, consistent temperature at the point of use. Inside the valve, a thermostatic element continuously senses the mixed water temperature and adjusts the flow of hot and cold water to maintain the pre-set outlet temperature, even if there are changes in pressure or supply temperature elsewhere in the system. If the hot water becomes too dominant, the valve reduces its flow and increases the cold supply, and vice versa. For safety, TMVs also include a fail-safe mechanism that rapidly shuts off the hot water if the cold supply fails, helping to prevent scalding while allowing hot water to be stored at higher temperatures for hygiene and Legionella control.
Why request a Thermostatic Mixing Valve (TMV)?
Thermostatic Mixing Valves (TMVs) to protect people from scalding while allowing hot water systems to operate safely and in compliance with regulations. Hot water must be stored at high temperatures (typically 60°C or above) to control bacteria such as Legionella, but water at this temperature can cause serious burns in seconds. A TMV reduces the water temperature at the point of use to a safe, controlled level and keeps it stable even if water pressure or temperature changes. TMVs also include a fail-safe function that shuts off the hot water if the cold supply fails, reducing the risk of injury. As a result, TMVs are essential in homes, public buildings, and especially in healthcare and care environments to meet safety standards, protect vulnerable users, and fulfil legal and duty-of-care requirements.