2 stage was designed more for comfort than savings. The board will time the second stage if your thermostat is single stage.
Your furnace should always start on low fire and then shift to high fire after approximately 10 minutes of run time. If you want high fire to operate on a second stage call from the thermostat (temperature drop in the room) you will need a 2 stage thermostat. Simply call a contractor and have one installed if you want it to operate this way.
There is nothing more frightful than ignorance in action....Mark Twain