Installed Carrier 3 ton 2 stage R-454B condenser and evaporator coil. Installed Carrier vertical gas furnace with new filter base. New gas pipe and flue pipe connections installed for the furnace. Installed Ecobee pro thermostat. Built and installed new extended supply plenum. Ran new low voltage wire to the thermostat and to the condenser in conduit. Installed new disconnect box and pad for the condenser. Connected existing flex duct to new plenum. All duct connections sealed with mastic/hardcast. Rebuilt primary condensation drain with new safety switch on the secondary. Pressure tested system with nitrogen and pulled vacuum. Cleared condensation drain with CO2 and primed trap with water. Tested heating and cooling operation. Everything is working at completion of service.