we recently power flushed a central heating system in atherton wigan ,see video below system was a normal open vented system feed tanks pump and hot water cylinder in loft ,customers radiators were cold and boiler was making ketling noises ,ie sludge and rust geting drawn round system,we power flushed the system and put inhibitor in and system was much quieter and radiators heated up nicely after the flush if you require any advice if you are considering having a power flush give me a call or email me through ouir website Tel 07836 353 985 or 0161 440 9675