power flushing is better but if you go round one by one and take tha radiator out side turn it upside down and flush with a hose pipe till water runs clear, do this to all radiaators then refit them, and add a cleanser via the header tank, leave this in for a week and drain system, let the ballvalve run till the water is clear. then refill adding a good inhibeter to the header tank. check with the system on that the pump is set correctly so no water is flowing over in to the tank from the vent pipe,as if it is it will add air to the system and cause further corrosion.
amh, December 2008
