Arrived on site for an ecobee installation that client provided. His old nest thermostat has a 4 wire application and the ecobee needs a common wire. We removed the old thermostat and left it on site for client to use elsewhere, removed the 4 wire thermostat wires, pulled in 5 wire thermostat wire and mounted the new ecobee leveled on the wall. We hooked up all neccesary wires at W, G, Y, C and R, let the thermostats calibrate and cycled in heat to test operation. The system is straight AC with heat strips so we set the system up as a traditional unit so the W wire powers heat strips with a call for heat. Client thanked us for coming out, we cleaned up and ensured system was fully operational upon departure. Call complete.