Problem started when 2 radiators were not heating. When balancing, I forgot to turn the boiler off. Now four different radiators are not heating. Boiler was running after I finished balancing but the pressure was zero. I have no idea now. I have drained and refilled the system, but it did not help.
Close TRV's on all rads that heat up ,and 3 rads that do not. Leaving one rad with its TRV open and it's lockshield half open. Run heating till that rad heats up. Then move onto next rad that doesn't heat and open its TRV,that should now heat up. Report back on the results
Just to be clear, do I also close lockshield valves on all radiators except the one that is left half open.