Out of the five homes I showed today to one of my buyers, not one had heat over 50 degrees. When it is really cold inside the house, it is difficult for my buyers to feel like home and hard to concentrate on what is important about the home because they are ready to leave when they get there because it is too cold. The comfort we want the buyer to feel is a "home like" feel so they can picture themselves in this home as their own. When you can see your breath from the inside it doesn't help. Just a tip to help sell your home!
Even if your home is vacant, at least when you have majority of showings . . . such as weekend, turn to heat up a little to give it a warm feeling to help sell your home.