CALC indicator on Krups FME4 coffee maker

I've owned this machine for several months (not a heavy user, 2-3 pots on weekends) and I've used it more in the descaling process, because the CALC indicator is on, than I have for making coffee. Most recently, I ran the descaling agent through according to the manual, then rinsed with 3 pots of clean distilled water and after the first pot of coffee I made (with distilled water) the CALC indicator is back on.