Drain system ,open all rads air vent,close main water supply to boiler,drain all access hot water via kitchen tap,undo hot water heat exchanger,clean out with sprit of salt,for health and safety wear hand gloves and mask ,clean out with fresh water,fit exchanger ,refill system open air vent one by one on rad,take air from pump big nut on pump,make sure automatic air vent is full open""...hot water
ltd, December 2011
