This probably is for people using Crown amps as sound reinforcement more than at home..... I have a few in for service and it was suggested to turn up the "fan on" timings.
On older xti xx00 series and the install cdi and dsi series, you can set the fan speed by the front panel controls. The software on the newer xti02 series won't allow this. You have to set the fan speed control in the software with a computer. I just figured out that you have to do this for any preset you make!
So if you set the fan to early on, as you should, you have to do this for each preset on each amp, and store each with the new setting.

I'm not sure if this was designed, or a glitch? I figured setting the fan to early on in the advanced settings of the software, would apply to all the presets. Yet when I looked at them, the fan reverted to normal setting? So I had to change it for all the presets.
I also noticed on a brand new XTi4002 that once the fan activated early, it did not turn off as I expected. I let it run for around 20 minutes to see if it would shut off when there was no signal. It was cool outside the amp. It just kept running? So I imagine this might not be a desired setting for average home use? Again, it was recommended by the service tech to protect the amp better.