The discharge air sensor failed on my harmony 2 zoning system so I'm left to upgrade to the harmony 3 system. I've read the manual for both and they appear to install similarly. I know I need 5 wires from the thermostats instead of 4. The wiring for the dampers appear to be the same. I'm most concerned about the wiring from the furnace. I have a G61, but the control board has been replaced. Does anyone have experience doing this and can offer any tips?