I performed a comprehensive furnace maintenance service, which included a thorough inspection of the furnace's components to ensure optimal performance. I checked the burners, heat exchanger, and air flow to identify any potential issues. Additionally, I cleaned and lubricated the moving parts, adjusted the thermostat, and tested the safety controls. I also provided a detailed estimate for duct cleaning, which involves removing accumulated dust, dirt, and debris from the ductwork to improve indoor air quality and enhance the efficiency of the heating and cooling system.