According to a study by the Lawrence Berkeley National Lab, nearly 90% of Americans say they’ve rarely (or never) programmed their thermostat because they’re not sure how to do it.

But it’s really not that hard, and it’s definitely worth doing because it can save you up to 15% a year on energy costs.

The first step is to pick the thermostat that best suits your scheduling needs so you can “set it and forget it,” an approach the U.S. Energy Department advocates to get the most savings.

Pick the Right Thermostat

There are four types of programmable thermostats, each with a distinctive scheduling style:

7-day programming. Best for individuals or families with erratic schedules, since this is the most flexible option. It lets you program a different heating/cooling schedule for each day of the week.

5-1-1 programming. One heating/cooling schedule for the week, plus you can schedule a different heating/cooling plan for Saturday and Sunday.

5-2 programming. Same as 5-1-1 programming, except Saturday and Sunday will have the same heating/cooling plan.

1-week programming. You can only set one heating/cooling plan that will be repeated daily for the entire week.

You’ll need a program for both the cooler months and the warmer months.

TIP: Before buying a programmable thermostat, identify the type of equipment used to heat and cool your home so you can check for compatibility. For example, do you have central heating and cooling, or just a furnace or baseboard heating? Otherwise, you may not reap the rewards of energy savings and may risk harming your heating and cooling equipment.

Change the Factory Settings

Most programmable thermostats have a pre-programmed setting that’s supposed to be for the typical American family. But what family is typical these days? You need to adjust the thermostat’s settings so it’s in sync with the life you and your family lead instead of some mythical family.

Programming options are based on:

• Wake Time
• Sleep Time
• Leave Time
• Return Time

The U.S Department of Energy suggests the following settings in order to shave up to 15% off your energy bill:

Winter months:

• For the hours you’re home and awake, program the temp to 68°F.
• Lower by 10° to 15° for the hours you’re asleep or out of the house.

Summer months:

• For the hours you’re home, program air conditioning to 78°F.
• For the days you don’t need cooling, manually shut off the AC. Keep in mind, it will kick back on if the house gets too warm.
• Program the AC to shut off during the hours you’re out of the house.

Here are a few programming timing tips that can help you create the best set-it-and-forget-it heating and cooling schedule for your home:

• Shut down heat or air conditioning 20 to 30 minutes before you leave home each day.
• Turn on heat or air conditioning 20 to 30 minutes before you come home each day.
• Reduce the heating or cooling 60 minutes before you go to sleep each night.
• Increase heating or cooling about 30 minutes before you wake up each morning.
• Spend time tweaking your program for a few days to make sure it feels right.

TIP: With a Wi-Fi-enabled thermostat, you can control your home’s temperature while on the go. That way, you’re not wasting energy if you’re running late or forgot to create a new program before going on vacation.

FYI: A furnace does NOT have to work harder to warm a house after the temperature has been set low during the day.

Use a Wifi Thermostat to Make It Super Easy

Want something that’s simpler? Newer more high-tech models have simplified the process:

The Nest Learning Thermostat: It creates a custom heating and cooling schedule for your home based on motion detection technology. Plus since it is Wi-Fi, it can be controlled remotely. Price: Usually a bit more than $200.

Honeywell Wi-Fi Smart Thermostat: This device makes it easy to create a custom heating and cooling plan. Unlike conventional programmable thermostats, it has a large color interface that displays a simple menu that walks you through all the programming steps. It also “learns” your home and will send you personal notifications if the temperature is not right, or if there’s a power outage. Price: Usually under $200.

FYI: Thermostats made prior to 2001 may contain mercury. To see if your programmable thermostat contains mercury, check with the manufacturer. If you decide to dispose of a thermostat that contains mercury, check out how to do so safely in your area at Thermostat Recycling Corp. (Not sure why mercury is so bad? Here’s the skinny: It’s toxic and it never breaks down. When it enters the waste stream, it permanently damages the ecosystem.)