On arrival all 3 systems running and heating. Garage furnace hit high limit and shut off but would not replicate issue once dirty filter replaced. Return plenums dusty, recommended duct cleaning and filter upgrade. Found beginning signs of biological growth in supply plenums, recommended iaq 200 uv system to kill on surfaces and in airflow. Recommended whole home surge protection to protect all electrical in home including HVAC system. Also recommended compressor saver kits to reduce wear on compressor on start up.