If the measured temperature rise is higher than the range shown on the furnace rating plate, what action should you take regarding the blower speed?

When the measured temperature rise is higher than the range specified on the furnace rating plate, it indicates that the blower may not be effectively circulating the air throughout the system, causing the temperature of the air to exceed the recommended limits. Increasing the blower speed helps to move more air through the heat exchanger, leading to better heat distribution and a more efficient operation of the system.

This adjustment can help prevent potential damage to the furnace due to overheating, as excessive temperature rise can strain the heating components. It ensures that the air flowing into the living spaces is tempered appropriately and avoids issues related to system inefficiency or safety hazards. Therefore, when faced with a temperature rise that is higher than acceptable, increasing the blower speed is a proactive approach to maintaining proper function and safety of the furnace system.