It means that the hydrogen production electrolysis plate, which is located at the base of the bottle, is not functioning properly as it may be clogged. For first time user, it is recommended to soak it in warm water for 30 minutes. (You can refer to the steps in question 1c) For regular user, it is recommended that you clean it at least once a week. (You can refer to the steps in question 9c) If it is not used for a long time, it may cause the SPE proton membrane to dry out. It is recommended to soak it in warm water for 4-8 hours before using it.