I have a new pressurised system as of this winter. My storage consists of three vertical storage tanks that were from a laundramat. The tanks had a considerable amount of water sediment and what looked like rust buildup on the surface. The tanks are glass lined so cleaning was easy except for the discoloration of the tank walls. I had to drain my system for some upgrades and I noticeed the boiler water was very reddish and brown. System was fixed and refilled. Would it make sense to keep draining and heating until water remains clear or just leave it alone? I dont know if the dirty water is harmful to the system?