I sometimes see a bit of airspace under the false bottom due to slower drainage through wet grains. Picobrew says that is OK. If the grain is compacting as severely as you describe, that doesn't seem OK. The crush is probably too fine. I open my mill up to .045 for Z brews.
The errors you report mean that the heating loop temperature is too far away from the wort temperature (heat exchanger isn't being effective). This usually indicates poor water inflow. That is usually caused by air leaks or clogged poppets on the input side.
The errors you report mean that the heating loop temperature is too far away from the wort temperature (heat exchanger isn't being effective). This usually indicates poor water inflow. That is usually caused by air leaks or clogged poppets on the input side.