The key components of a boiler that require regular inspection and maintenance include the burner, heat exchanger, pumps, valves, and controls. The burner should be inspected for proper combustion and adjusted as needed. The heat exchanger should be cleaned to ensure efficient heat transfer. Pumps and valves should be inspected for proper operation and lubrication. Controls should be checked for proper function and calibration. A qualified service technician should perform these tasks to ensure the boiler operates safely and efficiently.