Which of the following is not required to be inspected in heating systems?

The correct answer identifies that heat exchangers, while essential components of a heating system, are not always required to be inspected as part of a standard home inspection. This is because the inspector's role focuses primarily on the visible and accessible components of the heating system. Heat exchangers can sometimes be hidden or require specialized knowledge and tools to inspect thoroughly, which may not be within the scope of a typical inspection.

In contrast, furnace filters, installed heating equipment, and hydronic heating components are crucial for the system's functionality and efficiency, and they typically are part of the inspection process. Inspectors check furnace filters to ensure they are clean and replaceable, as clogged filters can impede airflow and efficiency. Installed heating equipment is also inspected to confirm that it is functioning properly and meets safety standards. Hydronic heating components may include pipes, radiators, and control systems, which are visible and accessible during routine inspections and are therefore included in the assessment.