I have recently moved into a house approx 20 years old. Some of the radiators have been replaced and some not so I am going to replace them all over the summer as the older ones have been painted several times and look shabby as well as having some bad corrosion around the bleed valves.
My question is whether I should flush the system through with a sludge/scale remover or not to clear the pipework. I have had various views on the subject some saying yes and others saying no because there is a chance that flushing could open up any small leaks that have self sealed/scaled up over the years.
Am I going to cause myself more problems by flushing the system with a chemical or should I just drain down and refill several times over with just plain water ???
Any comments from past experience would be most appreciated.