19JAN2024 Jason Brown Arrived for call back on recent no heat. Spoke with homeowner about the systems performance. They explained that the system is doing the same thing. It will just start blowing cold air. Inspected equipment, ductwork, insulation and filter. We found that the system has ~420 CFM and calls for 780 CFM in heating. This is causing the system to trip the high limit during longer run times. Discussed sizing, and airflow. We decided to move forward with a return cut it. Will call Monday for scheduling.