Changed d/s radiator, can't get u/s ones to fill

[Rainstone]

I have changed a hall radiator which is on an inverted loop, having drained the loop first. When I came to refill system I eventually got the radiator to fill but when I tried to bleed the upstairs radiators, nothing happened. The system has a gas back-boiler behind a gas fire. The airing cupboard is right behind it (downstairs). The boiler fires OK and the kitchen radiator gets very hot but none of the other rads in the house do. There is water in all of the downstairs rads, but I don't get any water out of the upstairs radiators bleed valves and only a slight sound of air being expelled.

I tried turning off the d/s radiators to force the upstairs circulation but no luck. Do I need to bleed the pump? Feeling the pipe going upstairs from the pump it does not get warm. There was a lot of black magnetite in the radiator I changed. Might there be a blockage? I have not yet checked the header tank but I could hear water running.

I don't have any heating now. Some urgent help appreciated!

 

[Plumber Will]

Try bleeding the pump...is the pump actually running.

 

[Rainstone]

Problem solved. Ball valve in header tank was jammed so the header tank was empty. Doh!