Not changing the cartridge filters or replacing the demineralizer resins when the differential pressure calls for it will accelerate the plugging of the stator bars. Closed-loop systems have a reduced chance of contamination, but they are not maintenance free. Reducing the contaminants and debris in the system extends the life of the entire system by lengthening the amount of time before components need replacements. Remember that it is much easier to prevent bacterial contamination than it is to try to recover from a system that is severely contaminated. Deal All , The Highest point of system is only 6 meter's higher than the makeup water pump set , its already located on roof top , Can i just simply connect the Makeup Like to the Main Line of Chilled Water return , or should i make the Connection into the Air Separator , The Air separator vent pipe extended above the air separator , is the most highest point the whole system?? Some plants blanket the head tank with nitrogen, or even hydrogen, to preclude any air.