How to Program a Programmable Thermostat

Thermostat program being adjusted by hand

The Spruce / Nelly Cuanalo

Project Overview
  • Working Time: 5 - 10 mins
  • Total Time: 5 - 10 mins
  • Skill Level: Beginner

Thermostats regulate the climate in your home by telling your HVAC system when to heat and when to cool, as well as when to circulate air using a fan. A traditional thermostat can only be controlled via a simple temperature setting, but a programmable thermostat can be curated to your schedule, leading to lower energy costs without sacrificing comfort. Additionally, smart thermostats can be controlled with your smartphone and tablet, while some versions can even learn your habits and adjust independently.

If you still have the older rotary thermostats in your home, it may be time for a change to a programmable thermostat, and we have made programming them simple with this how-to guide. By installing a programmable thermostat or smart thermostat, you can save energy and see big savings on your heating and cooling costs.


Many energy companies offer rebates or discounts for customers that swap a traditional thermostat for a programmable or smart thermostat, as this reduces their energy usage as well as the customer's costs.

Differences Between Programmable and Smart Thermostats

Programmable Thermostats
  • Adjusts temperatures according to a schedule

  • Always follows temperature schedule (even when you're not home)

  • Does not make notifications

  • Must be set by hand

  • May be less expensive than smart thermostats

Smart Thermostats
  • Can adjust temperatures for scheduled events

  • Can notify you of maintenance needs, energy usage, and more

  • Controllable over WiFi

  • Can make automatic adjustments

  • Can adjust temperatures when you return home

Before You Begin

Before programming your thermostat, take note of your and your family's schedule. If someone is home during the week, it may not be possible to allow the thermostat to raise or lower the temperature during that time. The easiest process is to jot down your schedules before you start for easy reference.

What You'll Need

Equipment / Tools

  • Smartphone or tablet (smart thermostats only)
  • WiFi connection (smart thermostats only)


  • Batteries


Materials and tools to program a thermostat

The Spruce / Nelly Cuanalo

Programming a Programmable Thermostat

Most programmable thermostats offer a weekday/weekend split (5/2), a weekday/Saturday/Sunday split (5/1/1) or a seven-day split, which allows you to customize the temperature regulation on each individual day. If you are a person that maintains a consistent work schedule throughout the week, a 5/2 split may be the right choice for you. If not, a more customizable solution may be of interest. 

  1. Install Backup Battery

    Install the backup batteries that will maintain the memory in the event of a power failure.

    Backup batteries installed on back of programmable thermostat

    The Spruce / Nelly Cuanalo

  2. Set Date and Time

    Set date and time on the thermostat.

    Time being programmed into thermostat

    The Spruce / Nelly Cuanalo

  3. Use the Manual to Familiarize Yourself With Your Thermostat

    Follow the instructions provided by the manufacturer to program your specific thermostat. On most units, there are two different settings: heating and cooling. There is also a fan setting that controls whether the fan runs constantly or only when heating and cooling.

    Thermostat instructions held in front of unit

    The Spruce / Nelly Cuanalo

  4. Program Your Desired Weekday Temperature Schedule

    First, set the heat for the weekdays by setting the switch to heat and selecting a program. Set the thermostat to a specific day and time, then set your desired temperature. You have the option to set different temperatures for different times of the day. For instance, you may want the furnace to turn down to 65 degrees at 7 a.m. when you leave for work but heat the home to 70 degrees when you arrive. Likewise, you may want the home to be cooler while you are sleeping. Repeat the process for the cooling function.


    When choosing your temperatures, it is not a good idea to allow your home to reach extremely low or high temperatures, even if you won't be there to experience them. This can lead to moisture damage, frozen pipes, and general wear-and-tear on the home. Always choose a moderate temperature range to circumvent damage.

    Thermostat temperature programmed for weekday setting

    The Spruce / Nelly Cuanalo

  5. Repeat Process for Weekends

    Since you will likely be home more on the weekends, you may want to tell the furnace and air conditioner to run more frequently. On the other hand, if this is a weekend home, you may only need the home heated or cooled during the weekend. That's the beautiful part about programmable thermostats: They are adjustable to your individual needs. Press the program button until the day of the week reaches Saturday, then set the times and temperatures you'd like. Repeat for Sunday. Some units only have a weekend mode that controls both days, while others offer individual curation.

    Thermostat temperature programmed for weekend setting

    The Spruce / Nelly Cuanalo

Programming a Smart Thermostat

The process of programming smart thermostats varies only slightly from programmable thermostats, as the end goal is generally the same. Smart thermostats are far more customizable, yet they are designed to fit a wide array of consumer needs and can do as little or as much as you want.

  1. Install Backup Battery

    Install the backup battery for power-loss protection. If your device is hard-wired, skip this step.

    Checking the battery on a hard-wired smart device

    The Spruce / Nelly Cuanalo

  2. Determine Easiest Setup Process

    Read your manual to determine whether or not your smart thermostat is more easily set up using your smartphone or the unit itself.

    Instructions held in front of smart thermostat for setup

    The Spruce / Nelly Cuanalo

  3. Connect to WiFi

    Connect your thermostat to your home's WiFi.


    Whenever you use smart devices such as thermostats, door locks, cameras, and speakers, always use a secure WiFi connection with a strong password to protect your privacy.

    Smart thermostat connected to Wifi

    The Spruce / Nelly Cuanalo

  4. Set Date and Time

    Set the date and time on your unit.

    Date and time programmed into smart thermostat

    The Spruce / Nelly Cuanalo

  5. Set Temperatures

    Depending on your preferences, your smart thermostat can heat and cool in different ways. Most models allow you to select heat, cool, or heat and cool, as well as off. Heat and cool will allow you to set multiple temperatures which your thermostat will use as a guide to run your furnace and air conditioner accordingly. Once you determine your desired function, set your temperatures accordingly. On most units, this is a good time to set when your fan will circulate air as well.

    Temperature setting programmed in smart thermostat

    The Spruce / Nelly Cuanalo

  6. Set Scheduled Temperatures

    A smart thermostat is fully customizable and will allow you to set multiple temperature changes for every individual day. Customize each day according to your schedule and input the scheduled heating and cooling using either your smartphone or the thermostat itself.

    Temperature schedule programmed in smart thermostat

    The Spruce / Nelly Cuanalo

  7. Adjust If Needed

    The great thing about smart thermostats is how easy they are to adjust. If you find that your schedule is changing or your initial programming is not ideal, simply use your smartphone to make changes. If you have a week-long vacation coming up, many thermostats will allow you to schedule a specific heating and cooling plan for that week ahead of time—or even make adjustments while you're away through the smartphone app.

    Smartphone app making adjustments to thermostat

    The Spruce / Nelly Cuanalo