I performed a comprehensive heating maintenance for a customer to ensure safe and efficient operation. I began by inspecting the thermostat and replacing the air filter to maintain airflow. Next, I cleaned the burners and heat exchanger to improve efficiency and checked the ignition system for proper functionality. I tightened electrical connections, lubricated moving parts, and tested safety controls like limit switches and pressure sensors to ensure the system operated safely. Finally, I measured airflow and temperature rise to verify performance. I documented findings and shared recommendations with the customer, ensuring their system is ready for the heating season.