Earlier quoted context omitted.
Per wikipedia, it can form biofilms on pipes that will slough off. But the heater is still hitting high enough temperatures to kill it.
Yeah, but only if it is flowing across the deposit. If you do the "bare minimum 140f once a day" method, you have to flush all the hot lines with this for long enough to kill it. All this also presumes correct thermostatic calibration and generally even temperature distribution in a system planned to age with minimal maintenance. The process isn't instant, you also have to ensure the hot water hits all the lines down…
Where I am, you’re not allowed to deliver water to fixtures higher than 49C (120F), to reduce scalding risk. and this is usually accomplished through a mixing valve at the hot water tank outlet.
11m people live here, haven’t heard of any evidence of increased legionnaires: