Potterton Netaheat 10/16 Mk II - F heats up and cuts out?

SOUNDS LIKE THE PUMP NOT WORKING ,OR AIR LOCK. IF U NO ITS THE PUMP ON EITHER SIDE OF THE PUMP U WILL FIND U CAN ISOLATE IT, IT WILL BE EITHER SCEWDRIVER SLOT OR A SQUARE , SHUT THEM THAT WILL ISOLATE PUMP ,MAKE SURE U'VE TURNED OF YOUR BOILER AND ELECTRICS TO THE PUMP UNDO THE TWO LARGE NUTS EITHER SIDE OF PUMP THAT WILL RELEASE THE PUMP, JUST PLACE A CLOTH UNDER PUMP TO CATCH A BIT OF WATER THATS IN PUMP . THAT CAN BE TIGHT SO GIVE IT A GOOD SOAK IN WD40 FIRST. JUST MAKE SURE U TAKE NOTE WOT WAY PUMP CAME OUT ON THE REAR THERE IS A ARROW INPRINTED IN PUMP SHOWING WATER DIRECTION.

HI-SPEC PLUMBING
July 2006