Recently I had a duct type halcyon inverter installed. One unit is in the attic and the other in the basement. As I have read, you already addressed the issue of the indoor units set at the factory to read the temperature instead of the thermostats. This may have been a good idea with split units, but the attic unit was working too hard and the basement unit not hard enough. That was fixed when myself, and later the installer, found out that the thermostats are set at the factory to allow the ducted units to determine the temperature. After a few calls we were able to change that. The problem started when the power went out over night and I went to work early. When I returned home, I found that the units returned back to factory settings. I was able to change it back again, but since i leave the house vacant in winter, this brings up a real problem. What happens when the power goes out with no-one home? The attic unit will run and never reach set temperature since no heat is distributed up there. The basement unit will do the same but not as drastically. Fujitsu was not much help since they state that their thermostats are proprietary. I inquired if their was battery back up that would hold the program, but again no help. Is there a fix since I was forced to leave the unit off this winter much to my dismay. I was hoping to have the unit as a backup to my oil heat. This is a problem I am sure is bound to affect people other than myself. Thank you for any help you are able to provide