Stop turning your thermostat way down or up when you're not at home. It does NOT save you money. Your home is acclimated to the temp already, so turning it way up or way down makes everything in the house cold or hot which in turn your furnace or AC has to heat or cool everything in the house to the temp it was before you left. The unit runs longer doing that than just running its normal cycle.
One of our clients we told her to try it for a week and she couldn't believe how much it saved. She got her daily electric usage from the electric company and told me it's a dramatic difference.
Moral of the story: Stop Turning that thermostat up and down!