On my rig the bedroom thermostat does have a furnace setting but doesn't do anything the only furnace control is the downstairs thermostat which controls furnace for the entire rig. If you have the downstairs thermostat fan setting on anything other than auto when you use the furnace the AC fans will blow but the AC won't come on. To get the whole thing to work correctly, in my rig, you leave the bedroom thermostat off and set the downstairs thermostat to auto fan and furnace.
Dick, Joyce, Diego, Picatso and Gustav
2017 3720 RL, MorRyde pin box
2017 3500 Dodge Maxi DRW 4X4, Pullrite Hitch, IS, Disk Brakes, 3rd AC, Winegard Traveler, Bathroom door mod, Dometic 320, couch for desk swap, etc.