I completed an installation inspection on a Five Star 80% 90,000 BTU Gas Furnace 4T 21". Completed installation checklist. Installed 3” flue, installers tried using 3” - 45 into street 45. This did not work, cut that out and added 45 with 5” piece into another 45 and had 0 issues running the rest of the way. Installed Carrier infinity thermostat and explained basics to customer. During start up , had issues locating outdoor unit. Rewired outdoor low voltage to green block and did the same @ furnace board. Set low and high gas pressures. Checked refrigerant levels. Cycled and monitored the system. Operating normally at this time.
