The water tank light will illuminate if the tank is empty, the tank is not placed correctly into the machine or the magnet in the tank is not moving freely to indicate to the machine that the tank is full or empty.
Please ensure that the tank is full, is pushed fully into the machine and that the magnet is moving freely. The magnet will slide up and down its chamber which is towards the rear of the water tank. Should the magnet not move, please contact us and provide us with a copy of the receipt to validate the guarantee if the machine was purchased within the last 2 years.