Completed furnace, maintenance and inspection. I checked amp draws and components. I tested airflow and temp splits. I cleaned flame sensor and wiped down furnace. I replaced air filter with customer provided air filter. There is a lot of drywall/construction dust throughout the ductwork and system. I showed customer photos and explained how that dust can continue to infiltrate the furnace and cause issues in the future. Customer would like to talk with spouse about the duct cleaning options. Furnace is running within manufacturer specifications at departure.