Displayng 2 error messages on a 16x02 display
I think before the disconnection is detected, it goes into overheating (maybe just for some milliseconds).
However, because there is a while (true) loop within the overheating part, it will never show the NO TC CONN error.
If you consider the NO TC CONN error to be higher than the OVERHEATING error, than check within the while loop of the OVERHEATING error also for the NO TC CONN error and display NO TC CONN when it is detected.