Do yourself a favor and install a programmable thermostat that automatically adjusts the temperature when you aren’t at home, or for different days of the week, times of day, etc. You get the picture! Most homes have these now, but this is something that an older home may not have been updated with, so it’s a great place to start on your energy efficiency journey. Be sure you look for the Energy Star Rating as this can be listed as a selling feature for your home in the future.
Homeowners can realize up to 15% in annual savings by programming the thermostat five degrees lower for 8 hours per day in the traditional heating season and 3 or 4 degrees higher in the summer months during the cooling season.
At our home we have it set to adjust higher late at night after everyone goes to sleep. It resets very early in the morning just before we get up to cool things back down. Just an idea about one way we use our programmable thermostat. There are many selections at your local hardware store and prices are very reasonable.