To save energy and money, you can lower the temperature for water heating. However, if you go too far, legionella feel really good - and can make you ill.
Legionella are environmental germs that occur in small numbers in ground and surface water. They also get into the water systems in the house. If they multiply there, it can lead to diseases. For example, when we inhale the pathogens with the atomized, misted water when showering or washing our hands. Consumer advocates explain that this can be dangerous, especially for people with a weakened immune system. Infections with flu-like symptoms or severe pneumonia can occur.
According to the information, legionella find the best conditions to multiply at 25 to 45 degrees. To prevent this from happening, the temperature in hot water tanks should be at least 60 degrees. At the tapping points you are on the safe side with a temperature setting of at least 55 degrees.
And what about so-called "Legionella circuits"? They briefly raise the water temperature to 70 degrees and then lower it below 60 degrees. However, the consumer advice center advises against this. This does not stop the germs from multiplying.
If you live for rent, however, you do not have the settings in your own hands. Sascha Beetz from the consumer advice center then advises: "Anyone who finds out as a tenant that the temperature of the hot water on the taps is only lukewarm should point out the risk of legionella to the landlord."
Legionella also thrive in standing water. In other words, wherever the taps are rarely turned on: in the guest bathroom, in the holiday home, on the outside tap.
According to the consumer advice center, legionella can migrate from these places into the entire pipe system. You can prevent that. This is done by disconnecting unused lines from the mains or flushing them regularly.
You should also take the latter to heart when you return home after a weekend trip. To do this, you open all the taps one after the other until fresh, cold water flows out of the tap.
