Programmable thermostats, first introduced over 100 years ago , are a type of thermostat that allows the user to set a schedule for different temperatures at different times. Most programmable thermostats also have a hold feature which suspends the schedule and effectively turns the thermostat into a manual thermostat. The idea of the scheduling feature is that users will set a warmer or cooler temperature when the home is unoccupied to save energy and money. Due to this assumed energy savings, some building codes and government programs began requiring the use of programmable thermostats. Unfortunately, due to human error in using these devices, many programmable thermostats result in more energy use than the basic manual thermostat.

One of the main objectives of smart thermostats is to reduce the issues involved with using traditional programmable thermostats. In order to understand how smart thermostats take on this task, it is important to understand the issues regarding programmable thermostats and how they affect energy consumption. Between 2008-2009, Florida Power & Light (FPL) provided 400 homeowners with programmable thermostats and monitored their heating and cooling patterns. Out of the 400 participants, 56% of users used the programming feature while the remaining participants did not program the thermostat and left it on “hold”. It was determined that the users who used the programming feature actually consumed 12% more energy than the non-programmers. This consumption increase resulted from higher overnight duty cycles associated with lower thermostat set points (i.e. lower temperature setting), due to confusion with setting the schedule. This study reveals that programmable thermostats will not necessarily save energy. The smart thermostat attempts to combat this issue by taking the user out of the picture and relying on sensors and computers to save energy.

Another study conducted on the issue determined that the biggest problem for programmable thermostats was the human using it. The technology inside a programmable thermostat is no doubt one of the most important factors in determining whether or not the thermostat will be successful in saving energy. But an equally important factor is the human who is using the thermostat. Unfortunately, many people who own programmable thermostats do not know how to use the thermostat or are not using all of the features that are offered. One study conducted a number of interviews, surveys, and observations to determine that the vast majority of programmable thermostat owners are not using the thermostats for their intended purpose. An online survey showed that 89% of respondents do not use the schedule feature on their programmable thermostat. Other results from the interviews and surveys show that a large number of people have misconceptions about heating/cooling and the use of programmable thermostats. One misconception is people believing that heating all of the time is more efficient than scheduling the heat to turn off. Another misconception noted in the study is that turning down the thermostat does not substantially reduce energy consumption. These misconceptions reaffirm the idea that the programmable thermostat itself could have all of the necessary tools, but if the user does not use them or uses them incorrectly, then these thermostats will fail at saving energy.

As a result of these studies and others like them, energy star suspended its labeling of programmable thermostats in December 2009. It became the goal of smart thermostats to address these issues by taking the human out of the picture and creating a thermostat that uses smart computing to truly reduce energy usage and cost.