Template:L1 Model II Firmware 1.5 Fan Update
This is how to read the Serial Number to tell if your system was shipped with Firmware version 1.5 or later. If so, the fan runs constantly and this is the correct behaviour.
Note: The grayed out characters may be different on your system.
If the underlined numbers are greater than 4284 then the unit was likely shipped with Firmware version 1.5, after October 2014. Note: There is no user installable update for units with earlier serial numbers.