I THINK THE IMPELLER ON THE PUMP HAS SHEARED OFF THE ROTOR OF THE MOTOR. THE HOT WATER ISN'T BEING DRAWN AWAY FROM THE BOILER HENCE THE REASON IT IS SHUTTING OFF. TO CONFIRM THIS- REMOVE THE CENTRE BLEED SCREW ON THE PUMP WHILE IT IS RUNNING. INSERT A SCREW DRIVER AND YOU SHOULD FEEL OR HEAR IF THE ...
