If temperature measurements indicate a rise of 80 degrees when a furnace nameplate specifies a rise of 40 to 70 degrees, what should be done?

When temperature measurements show a rise of 80 degrees, which significantly exceeds the furnace nameplate specification of 40 to 70 degrees, it indicates that the furnace is overheating or that there is an issue with airflow or system efficiency. Increasing the fan speed can help facilitate better airflow, allowing for more effective heat dissipation throughout the living space.

By increasing the fan speed, you can help maintain a more appropriate temperature rise across the system, ensuring that the furnace operates within its designed parameters. This action can prevent damage to the furnace components and improve overall system efficiency, contributing to a safer and more comfortable environment.