When I turn on the central heating it works for about 10mins until the water heats up then it cuts and I can hear bubbling in the boiler. None of the riadators are heating up.
When I bleed the radiators air comes for a while but no trickle of water.
When I vent the boiler no air or water comes out.
The pump is functioning.
When I tie up the ballcock in the attic the water level slowly drops.
Is the system dry? Is there a leak in the system?
Any help would be great as I am at a loss.
