DIY Doctor UK DIY Forums

UP UNTIL MIDWAY THROUGH THE LAST COLD SPEEL MY 2 RADIATORDS IN LIVING ROOM WORKED FINE,SUDDENLY THEY ARE FREEZING COLD,WHEN I BLEED THEM THERE IS PRESSURE THERE, AS IS ALL THE OTHER RADIATORS.
I HAVE DRAINED THE FULL SYSTEM,BUT THE TWO COLD RADS WERE STILL FULL, SO I DRAINED THEM, REFILED THE SYSTEM,ALL RADS FILLED UP, PUT HEATING ON, THESE SAME TWO RADS REMAIN COLD,
WHAT AM I MISSING?
WE HAVE A GLOWORM C30X BOILER, WORST THING WE EVER BOUGHT, STOPS WORKING AS SOON AS TEMP DROPS BELOW 10 DEGREES.
I HAVE TRIED CLOSING OTHER RADS DOWN..... NOTHING STILL COLD

Worth draining both rads individually into a tray or something similar. Onced drained disconnect and check both the flow and return valves are live by slightly opening them running water from each into a catchement untill the water runs hot. This will prove there are no air-locks or blockages
Chances are that the radiators, at the moment, are filling / pressurising from one end only.