You program a thermostat based on the instructions provided by the manufacturer. Through the settings, you can change the heating, cooling and fan. There are several settings that can be programmed into a thermostat that both reduce costs and keep the home comfortable.
Programmable thermostats have time settings, which give you the opportunity to set the temperature based on the day of the week and time of day. For example, if you wish to have your house cooled before you arrive back home, you can set the thermostat to cool the home before you arrive. Some units have a specific mode for weekends, which gives you the ability to set a constant temperature based on your daily schedule.
These thermostats also have a third setting that allows you to control the fan, which circulates air throughout the home. This setting can be used in conjunction with the heating and cooling system. With the auto setting, the fan turns on at the same time as the air conditioning and heating does. This keeps air moving while the thermostat is working.
It is vital to keep the manual on hand when programming a thermostat. Although many thermostats have similar settings; the way they work are entirely dependent on the brand and model of the thermostat you are using.