What is the minimum temperature in water that Legionella does not grow? (Ex: 150°F, 143°F) I need to know this to promote prevention of Legionella for the water heaters I sell. Is this the best method for prevention?
Legionella will not propagate at temperatures of 140°F (60°C). When the hot water leaves the tank, the temperature will drop. So, be aware that if Legionella is already in the distal sites such as pipes and faucets, the increased hot water temperature will not affect the Legionella elsewhere in distal sites. Maintaining hot water temperature at 140°F is not an effective method of disinfection for large buildings for that reason. However, if a systemic disinfection is carried out beforehand, (e.g.: superheat and flush or copper-silver ionization), hot water tank temperatures of greater than 140°F may minimize recolonization.