Also known as Legionnaires’ disease, Legionella got its name from an outbreak of an unknown “mystery disease” that sickened 221 persons, killing 34 people. The outbreak occurred among people attending a convention of the American Legion in Philadelphia in July of 1976. In January 1977, the cause was identified as a previously unknown bacteria which was subsequently named Legionella.

Legionella bacterium are commonly found in low concentrations in groundwater, lakes, and streams, and can be found in municipal water supplies. They reproduce to dangerous levels only after entering man-made equipment, such as water tanks, under certain conditions.

There is no vaccine.

There are no USA regulations requiring anti-legionella functions on a hot water heater.

Legionella growth can be prevented by providing temperature conditions that sterilize the bacterium.

Generally, water can be heated periodically to a higher temperature, and depending on the temperature achieved, hold it at that temperature for a certain period of time.

In the Chiltrix Anti-Legionella function, the tank is raised to a high temperature and held for a set period of time, every seven days (default setting). The user can select various temperatures and scheduling as desired.