My central heating system is coming up for 5 years. I have had numerous problems ranging from premature pump failure (4 in under 5 years) Boiler kettling and a pin hole radiator. It has been identified via an expert report that 1:insufficient flushing of the system 2:corrosion or flux residue and 3:system at risk of failure due to debris. Extremely high levels of copper found 32 parts per million when it should be less than 3 parts per million. An inspection on the pin hole radiator found black iron oxide(corrosion). Would a power flush fix the corrosion in the system or will i need to replace the full central heating system ? Any help greatly appreciated.