DIAGNOSIS The flashing 'Clean' light is a timer-based reminder, not a sensor. It triggers after approximately 60 brew cycles, regardless of whether you've descaled it. It just wants you to run the official cleaning process.
FIX To turn the light off, you have to initiate the programmed cleaning cycle. With the brewer off, press and hold the 'Program' and '12oz Travel Mug' buttons simultaneously for 3 seconds. All the lights will flash, and it'll start a cleaning cycle. You must have the carafe in place and the brew basket removed. Let it run its full course—it'll take about 15 minutes. When it's done, the clean light will be off.
IF THAT DIDN'T WORK If the light comes back on after a few brews, the internal counter might be stuck. Try unplugging the machine for a full 5 minutes to force a hard reset of the microcontroller. This often clears a glitchy reminder.
HEADS UP During the cleaning cycle, hot water and steam will come out of the spray head. That's why the brew basket must be removed—you don't want to scald yourself reaching in there. Just let it run into the empty carafe.