WHY SO HOT?

To kill off Legionella, the bacteria that causes Legionnaires disease, hot water should be stored at or above 60°C. Unfortunately, hot enough to kill Legionella means hot enough to kill or disfigure people too. Legionella bacteria will die above 60°C Legionella bacteria thrive between 20°C and 50°C. Legionella bacteria will not multiply at temperatures below 20°C, but will remain in the system as a potential threat.