Legionella cycle

A Legionella cycle is a controller-managed domestic hot water cycle that periodically raises a stored hot water cylinder to a specified higher temperature as part of the system's bacterial-growth control arrangement. In heat pump and cylinder documents the same idea may appear as Legionella protection, anti-Legionella protection, disinfection or pasteurisation, and the heat can come from the heat pump, an immersion heater or both depending on the product, wiring and settings. It is not the same as an ordinary hot-water schedule, immersion boost, cylinder thermostat setting, heat pump flow temperature, hot-water cylinder sizing, a risk assessment or proof that the whole water system is safe, compliant or correctly configured.