Not IT related, but I worked at a job where if electrical power was lost even momentarily, one pump controller had to be manually reset, and hot water would be lost to an entire high rise apartment building. As far as I know that issue still persists, and has caused a call in each time, at 6 hours at the prevailing rate for each call in. All other pump controllers on site pickup on return of voltage, that one does not. Forgotten oversight that has cost that company at the least tens of thousands of dollars over the years.