National Home Inspector Practice Exam 2026 - Free Home Inspector Practice Questions and Study Guide

When high levels of carbon monoxide are detected at supply air registers during an inspection, the most appropriate action is to open windows, shut down systems, and advise immediate evaluation by an HVAC contractor. This response addresses the immediate safety concern posed by carbon monoxide exposure, which is a serious health risk.

Opening windows provides ventilation to dilute and disperse the hazardous gas, reducing the concentration in the living environment. Shutting down the heating or ventilation systems prevents any additional circulation of carbon monoxide throughout the property. Finally, advising that a qualified HVAC contractor evaluate the systems is crucial for ensuring that the source of the carbon monoxide is identified and remedied, protecting the health and safety of the occupants.

This answer emphasizes the importance of immediate safety measures while also ensuring that a professional evaluates the situation to prevent future risks. Other options do not adequately address the urgency of the situation or the necessary steps to ensure safety.