50 mins ago, medm on Sun machine is frozen, most channels are inactive (except  ACAV_HEATER, and it goes up to 7 which is the maximum value). 

I reboot the PSL crate, but ACAV_HEATER is still at 7 and heat up ACAV to 39 C.

So, I realized that I had to reboot another crate. Now ACAV_HEATER is at 4.6 and decreasing.

Now the system should try to bring the temperature back and might take many hours.