Programmable thermostats.(RATINGS)(Buyers guide)

Programmable thermostats can help save energy by automatically raising or lowering temperatures at night and when you're away. But confusing controls on some can make it easy to burn more energy than you bargained for.

The fact that some top thermostats can be hard to use is a primary reason the U.S. Environmental Protection Agency is reconsidering its Energy Star qualification. The agency is proposing an educational program, and will work with the industry to make thermostats friendlier.

Today's top thermostats have built-in energy-saving programs that are designed to cut heating and cooling costs by up to 20 percent, eliminating the need to create programs from scratch. But you'll still have to set the time, date, and the system the programs will control. Odds are you'll also want to tailor those programs to your schedule.

Our Ratings cover 25 models, including CR Best Buys that cost as little as $35. But months of testing confirmed that even some top thermostats make programming far more onerous than others, regardless of price.

Guide to the Ratings