I have an Intel NUC5CPYH with latest BIOS 0044. I've set the initial Fan speed to 0% in the BIOS, and the Threshold to 50°C. With that set, the NUC operates silent all of the time. However, sometimes when I reboot the NUC, the Fan immediately speeds up to maximum rpm and stays there. The only think I can do to make the NUC quiet again is to shut it down and power it up again (then the fan is off as expected).
So, is there perhaps a Bug in the BIOS or the Fan control of the NUC?