1-Drain heater 2-cut in valve to flush return line . 3- pump in sanitizer into hot water system. 4- flush return came out black for awhile pump in pre-mix 4 cans until return came back clean had chemical guy test return for sanitizer to make sure it was strong enough. 5- go around and run every sink to get sanitizer into faucets. Put in 3 More per mix cans pumped into system while run pump. (Note 6 areas that cannot run faucets.) 6-can not do one suite it is locked and cannot get into, Suite G also where water room is at there are 4 doors locked can not run those sinks either. Return 24 hrs later flush system out. Saturday flush hot water system so it is clear . Material used in notes.