Completed furnace tune-up maintenance per annual service agreement. Performed comprehensive system inspection including gas pressure verification, heat exchanger examination, and carbon monoxide testing with all readings within normal parameters. Cleaned flame sensor, burners, and orifice; inspected supply/return vents. Noted potential heat loss issues due to 16+ foot ceilings and undersized system (50,000 BTU for 2,600 sq.ft home). Recommended dehumidifier installation to improve comfort on basement level.