I just bought a new house that has a gas furnace. I was wondering what is the cheapest way to run it.
Right now I have the temp on my thermostat set to 64. When the temp gets to that number I turn the heater off and let the house cool down to around 58, then I turn it back on. I also turn it off all day when I'm at work, but when I get home the temp is in the mid 50's. Running the heat back up to 64 takes awhile.
I noticed if I keep my heat on though that it will run for ten minutes then shut off. It will remain off for only three minutes then turn back on and run for ten minutes again.
So is it cheaper to always keep it on, or to run it up to 64 turn it off and let the house cool down and then turn it back on?

Actually any setback of temperature will save energy but from 64 to 58 then back again is not going to save that much. Units have cycle time (so many runs per hour) built into the thermostat by a heat anticipator of sorts. Just the idea of having to play with the thermostat manually does not make sense to me but I have other things to do during the day like answering strange questions about playing with the thermostat.LOL Set it to 58 and let it stay there is you want to save energy or set it to 54 to save more energy or set it in between if that makes you happy. But set it and leave it alone.

Or get yourself a programmable tstat that keeps track of daily run-time and you can play with your setback temp to see what saves you the most money.

My gut tells me setting it back that far isn't saving you that much money, but the only way to be sure is have something that records cumulative daily run-time.

Thanks for the input guys.
I generally agree that I should put it at a certain temp and leave it there. The only thing that I have noticed that makes me not want to do that is that after the temp reaches it's goal it shuts off. That's good, but then 3 minutes later it kicks back on. It only runs for 10 minutes to go back up one degree, but then 3 minutes later it's on again. I just find it hard to believe my house isn't holding the heat in. Only 3 minutes down time seems a bit short. That thing will be running so much it's ridiculous.
Any I do have a programmable thermostat by the way. However I am not confident that it works like it should.

Replacing a thermostat that is malfunctioning can pay for itself in pretty short order. If your existing t-stat has any configuration options, they may not be set correctly for the type of system you have. Many times a good t-stat gets replaced needlessly, and just as often a new t-stat is not installed and/or set up correctly. Post brand/model/pic of your t-stat if possible-maybe it just needs some "tweaking". P.S. The cheapest way? Turn it off... consumes no gas and very little power. Wear LOTS of layers... :D