Removed an old 80% AFUE Rheem Classic Plus furnace in Northford and replaced it with a Carrier Infinity 98 modulating gas furnace. The existing unit had a cracked heat exchanger and was no longer cost-effective to repair. I modified the ductwork, installed a new PVC venting system, and connected a smart thermostat for better efficiency. After startup, I calibrated the system for proper airflow and combustion. The new unit runs quietly, provides better heating control, and will save the homeowner on energy costs.