I better sit down and refresh my memory on all the settings then, as I remember looking at how the Command Unit might be used as a complete programmer/controller/thermostat back when Joe90 found a cheap ASHP, some time ago, but I haven't pulled the manuals out and had another look since. Getting the unit running to test it is easy, but ideally you want to fill it and connect it to something like a coil of pipe, so you can get a feel for how it works.  You can make it run in cooling mode sim