Thermal Circulation Valves provide self-balancing, thermostatically controlled regulation of flow and thermal disinfection, assisting with protection against Legionella. The valves automatically adjust in response to changes in fluid temperature to ensure that stable temperatures are maintained across domestic hot water systems. There are legal requirements for designers and installers to consider the risk of Legionella.

Thermal Circulation Valves are designed to be installed in domestic hot water systems to help to "keep hot water hot" so that the Legionella bacteria cannot survive.