Whenever somebody’s home, your Nest thermostat can use Early-On to start heating or cooling early so your home reaches the scheduled temperature on time. Simple programmable thermostats only start heating or cooling at the time you schedule. They don’t take into account how long it takes for your home to heat and cool, so your home doesn’t reach the scheduled temperature until later.
Newer Nest thermostats need to be connected to a Wi-Fi network to use Early-On. When Early-On is enabled, your Nest thermostat automatically calculates how early it should turn on heating or cooling, so your home reaches a scheduled temperature on time.
Early-On works similarly to when you have to preheat the oven to make cookies. You typically start to heat your oven a few minutes ahead of time so it’s the right temperature when you’re ready to bake your batch of cookies. Now, imagine your oven knew the dough was ready to bake at 5:00 PM and would automatically turn to be 350°F (175°C) at around 5:00 PM.