Earlier I closed all apart the last one. Then it did warm up, othervise is stone cold.
Then you have flow through all the rads. You do not have a (total) blockage. You do need to Balance the radiators. You might need to turn up the pump speed.
I would suggest you balance the rads first; then fit a system filter, then do a chemical clean, then on final fill add X100 corrosion inhibitor; X200 for limescale breakdown, and the new X900 which will loosen remaining sediment so that the particles circulate in the water and can be trapped by the filter. You leave all these chemicals in permanently. Bale out all the mud from the F&E tank before you start work and scrub/wipe it clean. Fit a lid and insulating jacket of not already fitted.
Thanks JohnD!
What do you think this whole job could cost, I would not be able to do it myself?
I'm not keen on the Magnaclean, although it is spectacularly fast at trapping circulating black sludge particles, I think the Spirotech or Sentinel System filter, both made of brass not plastic, are better made and a similar price.