Kathryn did a good job in her post Wednesday debunking a myth and setting the record straight. The fact is, turning down your thermostat at night or while you’re away (in the winter) saves energy and saves money.
And yes, programmable thermostats do work. They can automate the process so you don’t have to remember. And so the house warms up before you wake up–or before you get back from work. Of course, they only work it you program them! Your heating contractor should show you how if you have any questions.
When programming you setback and recovery times, consider when you normally go to sleep and wake up, and when you and everyone else is normally gone during the day. It usually makes sense to program the temperature setback a bit earlier than you actually go to bed. In most cases you likely won’t notice the house cooling down as you get ready for bed.
Being an energy geek, I take it a step further with a “hybrid” approach. I use a programmable thermostat to turn the heat up and down automatically. But I’ve programed it so that it when it kicks back up is stops a couple degrees shy of the desired target. For example, rather than go all the way back up to 68, I set it at 66. If I’m late getting home I save a bit more. When the metabolism is cranking sometimes I don’t even notice, and I save again. The rest of the time I just manually move it up (and then the programming takes over again and moves it back down on the right schedule).