Diagnosed a heating issue where the system was not blowing warm air in a Trane XR95 furnace. Identified a malfunctioning igniter and a clogged filter restricting airflow. Replaced the igniter with a Trane OEM part, model IGN00145, and installed a new 3M Filtrete air filter, model UA23DC-6, to ensure proper airflow. Tested the furnace post-repair to confirm it was now producing warm air efficiently.