The old system doesn't have to come out
If you're adding a mini split alongside a furnace or baseboard heat, nothing about the existing system needs to change. The mini split runs its own line set to the outdoor unit and its own wiring. It doesn't tie into ductwork or a boiler loop, so the old equipment keeps doing exactly what it did before, just with less of the load if you choose to run the mini split as the primary heat for that room.






