How do I perform a cleaning cycle when the DESCALE/CLEAN light flashes?

Insert the cleaning disc into a filter basket, place it in the portafilter, put 1 cleaning tablet into the filter, and lock the portafilter into the group head. Turn the machine off, then simultaneously press and hold the 1 CUP, 2 CUP, and POWER buttons for 3 seconds. While holding the 1 and 2 cup buttons, press the power button. Repeat if the tablet hasn't dissolved. Wait 5 minutes, empty the drip tray, fill the water tank, and rinse the filter basket and portafilter before use.