Had builders in doing bits and we asked the plumber to flush a radiator as it was cold in a significant part of it.
He mentioned that we could fit a magnetic filter to the system as it would help reduce the problem occurring again. It would be "about £100".
So anyone know anything about them, are they worth it? Never had a house with one before.
It also occurred to me that there should be no corrosion products going round the system if we use a corrosion inhibitor. Is that easy enough to do yourself? How do you get it into a sealed combi system?