I think it’s specifically Legionnaire’s disease / legionella. Hot water tanks should periodically be heated over 50C to kill off the bacteria. See e.g. https://

I think it’s specifically Legionnaire’s disease / legionella. Hot water tanks should periodically be heated over 50C to kill off the bacteria. See e.g. https://www.hse.gov.uk/legionnaires/hot-and-cold-water-storage.htm https://www.hse.gov.uk/legionnaires/hot-and-cold-water-stora...