I performed a thorough furnace tune-up to ensure safe, efficient, and reliable operation. This included inspecting the heat exchanger for cracks and corrosion, verifying all safety controls, and checking the venting system for proper draft and obstructions. I cleaned the burner assembly, tested the flame sensor, and adjusted the fuel/air mixture for optimal efficiency. The blower wheel was inspected for dust, and airflow through ducts was verified. Electrical connections were tightened, and the thermostat was tested. The system was run through a complete heating cycle to confirm smooth operation.