To save energy, get with the programmable thermostat

Programmable thermostats can lower energy bills by roughly $180 a year, yet only half of thermostats installed in today's homes are programmed to lower temperatures when the house is unoccupied or at night, according to a study funded by the Department of Energy. The reason, says other studies, is that people find programmable thermostats too hard to use. And in Consumer Reports latest tests of 30 energy-saving thermostats, we did find some that were so difficult to set that you might give up in frustration. Fortunately, some others were simple to adjust.

About 37 percent of Americans have installed a programmable thermostat, according to a Harris Poll. Switching to energy-saving lightbulbs and searching for Energy Star appliances when shopping for replacements were more common energy savers. But you won't see the Energy Star on programmable thermostats. Energy Star stopped certifying them in 2009 mostly because they were difficult to use. New standards factoring in ease of use are being developed.

But why wait? Our thermostat tests found that most can keep rooms close to the chosen temperature and all the models have basic pre-programmed settings that will save you some money right out of the box. The eight recommended thermostats are easy to adjust—you won't have to look for the manual every time you want to make a change—and the screen displays are easy to see, even at night. We tested models from Venstar, Honeywell, Ecobee, Nest and others. Some of our standouts are more intuitive than others, one appeals to techies, and the best low-cost models are around $75. See our thermostat Ratings for details on performance and features.

—Kimberly Janeway