Thanks for the info. I'm a newbee, my first Thermal- I think this was a false alarm. Just got this thing Friday afternoon. What I was doing was toggling to the NUC as unit said calibration needed ,Toggle forward or back as this starts the NUC. It would say "calibrating close cover" then disappear. I was then pushing it again thnking it was in progress, & keep doing that to check. But what I was doing was starting the NUC process over & over again. Now I know hit it once & leave it alone, when the calibrate message disappears it's done!