Upon receiving a call regarding a malfunctioning furnace, I promptly arrived to assess the situation. Upon inspection, I discovered that the system was emitting dangerously high levels of carbon monoxide. After explaining the risks and potential solutions, I recommended replacing the heat exchanger. However, the client was not convinced of the benefits of this option. Instead, they opted to replace the entire system. I guided them through the process, ensuring they understood the advantages of a new system and the importance of safety. The replacement was completed efficiently, restoring comfort and safety to the home.