When the "CLEAN" icon is lit, it indicates it is time to descale the machine. Remove the filter basket and the water filter. Fill the water tank with 7 cups of fresh water, pour in the descaling solution (3.4 oz / 100 mL), turn the dial to "BREW", and press the "CLEAN" button. The "CLEAN" icon will start to flash indicating the descaling process has started. After 15 minutes the "CLEAN" light will start flashing faster. Then, empty the carafe and refill will 14 cups of fresh water, pour into the water tank of the machine, and press "SET" to start the rinsing process. After descale and rinsing is completed, it is suggested to run two full brewing cycles of fresh water without coffee to completely remove any residual solution.