@Jim Stewart Have you seen my house? If I can have someone help me carry it up it would take me 30 minutes and $30 in material, then probably an hour to remove all the air. All plumbing is available already.

If I have a loss due to elevation, why would I not get an increase when there is a drop?

When I look at other multi-split units, there are always two connections for each unit, so it does not make sense that those valves are to add additional lines.

Always been like this. Will call out a technican and see what they say.

KMJ Both units are like this, if units A is hot the other also get hot and vice versa. You can also feel how all four pipes gets hot. I actually tried rewiring and nothing happened, so indeed I dont think its a wiring issue but I do think either the valves are wrong or some issues with the board.

I am seeing the behavior described in the manual, I tried putting one unit on cooling and the while the other was heating, it did not work. But I dont believe that the unit is behaving as expected, when one unit is on it is still pushing hot gas to both units, where the unit which is turned of is releasing hot air through an expansion valve.

@HotLicks Drill a hole first.

@FreeMan I will update the original post.