This code means your water level has fallen below the minimum level of water needed. The machine will cut out for safety. Adding more water to the cooking vessel with solve the problem and you can reset the machine but please note that this may then reduce the water temperature until the new liquid has heated up again therefore slowing down cooking times. We suggest you reduce the risk by filling water to the maximum level before cooking and using a lid on the container to reduce evaporation especially for long cooking times.