Yesterday, I noticed that our furnace would kick on and turn itself right off without doing what it is supposed to do. Then no more than a minute later, it would do it again but work like it is supposed to. We keep our heat around 64-67 if that has anything to do with it (I doubt it since that is what it is always at). We have the original thermastat (round with a dial) and I was thinking about having someone install a digital one since I know it regulates temperature better. Any suggestions?