Found the reset button on the boiler, and central heating now working, so it seems that the header tank was low on water especially after rad falling down and leaking some water.
thanks everyone for their help, especially Ed Sirett for pointing out about the reset.
I think there is no blockage but it was shortage of water in the header tank. now I have cleared that but now the boiler has gone dead. i switch on the programmer for either c/h or h/w and the electricity spur light comes on and i rotate the thermostat on the boiler to max but the boiler does...
A radiator came away from the wall(plaster board),it had been in place fixed for 20 years. A small leak from both in/out pipes occured. I cut the in/out pipes(micro-bore) and just sealed them by flattening & folding them to stop the leaks.
But now my cental heating is not working. I have a...