Dear Glenn: With the increased costs of heating with natural gas these days, I have programmed my thermostat to 68 degrees during the day and down to 60 degrees at night. One of my friends thinks the 8 degrees difference is too much work for the furnace to recover and save me any money. I also leave my fan on 24/7.

Chuck, Detroit

Dear Chuck: The Department of Energy agrees with you, not your friend. A programmable thermostat will "learn" your lifestyle.

It will throttle down the furnace so that it is 60 degrees at the time you set it at night. Then it will throttle up the furnace so that it is back at 68 degrees at the time you have called for the temperature to rise in the morning.