If you have the Comfort Control Center thermostat, do you have a 4 button or 5 button? The new units use a 5 button and will not work on the 4 button thermostat. You will have to change the control board on the other unit as well as the thermostat and set the dip switches. Once set then reset the thermostat and you should be good to go.
Mike, RVIA & RVSA Certified Master RV Technician
Amy, Dr. Assistant - Roxie & Mei Ling, four legs each
2000 Gulf Stream Scenic Cruiser 450 hp & 1330# torque
06 Saturn Vue, 06 Chevy Z71 4x4 & 2014 Corvette Z51 M7