Want to cut your heating and cooling costs by up to 20 percent? You don't have to give up heating during winter or air-conditioning over the summer. All you need to do is install a programmable thermostat, which will automatically raise or lower temperatures at night and when you're away from home.

For more information on how programmable thermostats work and for basic buying advice, read this recent Q&A from the Home & Garden blog. Also watch the video below, which shows how we test thermostats.

Essential information: Use our Ratings and Quick Picks (available to subscribers) to find an easy-to-program thermostat for your home. If you plan to install a thermostat on your own, check out this primer on installation. And don't miss our expert advice for 10 easy ways to save hundreds of dollars on energy costs at your house.