Installed 3 ton Carrier R-454B condenser and evaporator coil. Installed Carrier gas furnace with propane conversion. Installed new disconnect box for the condenser. Installed Ecobee pro thermostat. Installed new secondary drain pan. Rebuilt primary condensation drain and added SS2 / SS3 safety switches. New gas pipe and flue pipe connections for the furnace. Built and installed new supply and return plenums. Sealed all connections with mastic / hardcast. Cleared drain with CO2 and primed trap with water. Pressure tested system with nitrogen and pulled vacuum. Adjusted gas pressure for propane operation. Charged AC with R-454B refrigerant. Tested heating and cooling operation. Everything is working at this time.