the first thing to do would be to obtain a radiator bleed key and check all of the radiators are free of air, after this try to locate the pump which would usually be in the cylinder cupboard and unscew the bleed cap from the centre until no air is present. after this switch on the boiler and check to see if the pump is vibrating, if it does and there is no heat coming from then then the problem is with the boiler itself. you could check if the pump has seized by removing the bleed screw completely and check it is rotating.
NHS GASMAN, March 2011
