magnetite

Hi. I have a 1960s house with a combi boiler fitted in 2009. Heating working well except for one rad which won't heat adequately. Patchy heat - along the top, some at one side. No air coming out when I bleed it. Am thinking sludge. I thought I'd loosen the hex blank at the other end to see what...

Had a veismann combi boiler fit 3 years ago along with a magnaclean 2 pro and kept up the servicing. At the weekend the boiler failed due to the smaller heat exchanger being blocked with small shards of magnetic material causing an F2 Burner fault. Despite it not really being a Boiler Issue...