Responded to service call for 9-year-old Daikin heat pump system (model FVXS15RVJU) with heating performance concerns. Diagnosed operating characteristics of indoor fan coil unit, determining system was functioning according to design specifications with normal defrost cycle operation. Explained to customer that initial low airflow is normal operation before transitioning to high speed mode, and that proper operation requires manual fan speed selection rather than auto mode for optimal heating performance.
