Another heat pump question

[CherriandBob]

We didn't really think much about how the heatpump/furnace operated until I read some of the posts here. Without sounding redundent could I get a quick explanation on how the heatpump/furnace operate. Is the furnace suppose to automatically come on if you have the heat pump on? It seems like someone said they switch when the temp drops below 40 or something like that. We have our unit in Elkhart as we speak having some work done. We asked the shop to check this for us and their response was for us to check it when we got there to pick it up and let them know how it works. Am I wrong to think that a factory authorized repair shop should be able to do some troubleshooting? Thought we would get some of these issues taken care of while still under warranty, but don't really care no if they aren't even going to try to look at a problem. Might as well wait and take care of it ourselves. Thanks for any input.