Yes, agree, but I shall do this with only one radaiator opened, then close it and go round the compete system, opening and closing radiator valves, so that maximum pressure is going through each radiator line.
After that it is the power flush, if that doesnt work
The pump is a Grundfos Selectric
After that it is the power flush, if that doesnt work
The pump is a Grundfos Selectric