How can the efficiency of an existing gas furnace be improved?

The best approach to improve the efficiency of an existing gas furnace is by installing a programmable thermostat. This device allows homeowners to better manage their heating needs by setting specific temperatures for different times of the day. For example, a programmable thermostat can lower the temperature while the home is unoccupied and raise it prior to the return of the occupants, which reduces wastage of energy. Additionally, it can adjust to outdoor temperature variations, ensuring the furnace only operates as much as necessary, enhancing overall efficiency and comfort.

This option focuses on optimizing how and when the furnace operates, leading to reduced energy consumption and lowered heating bills. The strategic use of a programmable thermostat makes the system more responsive and prevents unnecessary heating when it isn't needed, which contributes significantly to improving the efficiency of an existing gas furnace.