DIAGNOSIS The machine has a sensor that estimates scale buildup based on water usage and temperature. Sometimes, running a descale cycle doesn’t fully reset that internal counter.
FIX You need to manually reset the descale reminder indicator. Here’s how: 1) With the machine ON and idle (not brewing), press and hold the ‘Strong’ and ‘Hot’ buttons simultaneously for about 5 seconds. 2) You should see the descale light flash and then turn off. 3) Release the buttons. The counter is now reset.
IF THAT DIDN'T WORK If the light comes back on quickly, the sensor might be faulty, or there’s still significant scale in the heating element. Try using the official Keurig Descaling Solution, as it’s more effective than vinegar on hard scale, and run the descale mode one more time before resetting.
HEADS UP When descaling, you must follow the precise pause-and-pour steps shown on the machine’s display during the cycle. Rushing it or using too much solution can leave residue that triggers the light.