Article: If your home has central heating and cooling, then you most likely have a central thermostat to control it. Thermostats, whether programmable or not, will have many similar settings, including fan options, heating options, and cooling options. With fan options, you will most likely have "on" or "auto." By choosing "on," you will engage the fan on your system to circulate air through the home without heating or cooling it. The fan will run for as long as the "on" option is engaged. The "auto" option will only engage the fan when either the heat or air conditioning turns on and needs to be circulated. The "on" option for the fan is generally considered an energy waster since it will require a decent amount of energy to move that much air on a constant basis. Due to this most people only ever leave the fan set to "auto." Many people use the "on" option simply to flush air out of a houseif something burned while cooking and you want to circulate enough air to clear the smell, for instance. Depending on your model of thermostat, you will likely either have a small switch on the thermostat's faceplate or a cycle button to cycle between heating, cooling, and off options. You can prep the system to cool the home by moving the switch or pressing the button until you reach the "cool" setting. You will see a number on the thermostat display. This number is the ambient temperature in your home. Use the up and down arrows on the thermostat to set the temperature you want the home to reach. You will see a different display number come up that corresponds to the temperature you set. You will likely hear the system click as it engages and turns on the air conditioning to lower the temperature in the house to what you have set. The system will run until the house reaches the chosen temperature, and then it will automatically turn itself off and only reengage when the internal thermometer registers that the home is warmer than the set temperature. You can use the same switch or button to cycle the system to "off" at any time. Setting the heat for your thermostat is very similar to setting the cooling option. Use the same switch or button to cycle through until you reach "heat." You can then use the same set of arrows you used to set the cooling temperature to set the heating temperature. Again, the system will only run when the internal thermometer registers that the ambient room temperature is colder than the set temperature. You may also see an "EM heat" or "emergency heat" setting on your thermostat, especially if you live in an area prone to bitter cold conditions. This setting corresponds to a separate electric heating unit in the home in the event that the larger system breaks or freezes over during winter. While it does not hurt to test the emergency heating option periodically, you should stick to the standard heat setting for day-to-day use.

What is a summary?
Learn the differences between settings. Turn on the fan. Set the air conditioner. Set the heat.