Legionella Control

What is Legionella?

Legionellosis is the collective name given to the pneumonia-like illness caused by legionella bacteria. Legionnaires’ disease is a potentially fatal form of pneumonia and everyone is susceptible to infection. However, some people are at higher risk, including:

• people over 45 years of age
• smokers and heavy drinkers
• people suffering from chronic respiratory or kidney disease
• anyone with an impaired immune system

Where does it come from?

Legionella bacteria are widespread in natural water systems, e.g. rivers and ponds. However, the conditions are rarely right for people to catch the disease from these sources.
However the legionella bacteria can multiply greatly in water storage systems where the temperature remains between 20 and 45oC

How do people get it?

People can catch legionnaires’ disease by inhaling small droplets of water, suspended in the air, containing the bacteria such as a shower.

How is it controlled?

Legionella bacteria colonies can be destroyed by raising the temperature of the stored water to 60oC for a minimum of 10 minutes.
For water storage systems that do not regularly operate at 60oC or above it is recommended that a weekly heating cycle to 60oC is carried out. This will ensure that the water system stays free of the bacteria.

How can GEM Help?

The Apollo GEM has a programmable built-in legionella control cycle that can be used to automatically carry out this procedure each week. There are two programs available, one for each heater output. The cycle day, start time and required temperature can be independently programmed for each heater output.