Home/Away Assist will automatically switch your Nest thermostat to its Eco Temperature when you’ve left home, and will help save energy as you come and go. But if you plan to be gone for a longer period of time, setting your Nest thermostat to Off will save even more energy and help prevent damage to your home if the weather gets extremely cold.
You don't need to adjust your Nest thermostat to save energy each time you leave home. It can automatically help save energy by switching to Eco Temperature. But if you're going to be away for a long time, such as a holiday, you have a few options: manually set your thermostat Eco Temperature, set it to Off mode, or turn the power off to your system. Each of these has different effects.
Use Eco Temperature
Your Nest thermostat can automatically switch to Eco Temperature after it senses that nobody's home to help save energy. But you can also manually set it to Eco Temperature. Both of these options will keep your home relatively comfortable. So when you arrive home it should take less time to reach your preferred temperature than if you had set your thermostat to Off mode.
If you manually set Eco Temperature, your thermostat will stay in that mode and won't switch back to its regular heating or cooling schedule until you manually switch it to a heating or cooling mode.
If you let your thermostat automatically switch to Eco Temperature, and a neighbor comes by to take care of your pet or collect the mail, your thermostat could turn on your system to reach a regularly scheduled temperature. After they leave, your thermostat will switch back to Eco Temperature.
Set your thermostat to Off
If you plan to be gone for a longer period of time, such as a vacation, setting your Nest thermostat to Off mode can save even more energy than using Eco Temperature. But if you use Off mode your home might not be as comfortable when you come back.
Important: Off mode won’t turn your thermostat off, but it will make sure your system won’t heat your home unless your Safety Temperatures have been reached. For instance, water pipes can burst if they freeze. So if it gets very cold, Safety Temperatures will tell your thermostat to turn on your system and help prevent damage to your pipes.
Turn off domestic hot water
If you have a 3rd gen Nest Learning Thermostat that controls domestic hot water from a system boiler, you can also manually switch off your hot water schedule when you leave.
Otherwise, even if your Nest thermostat is set to Off, it will continue to follow your domestic hot water heating schedule for up to 48 hours after you’ve left home. After 48 hours, it will turn off your hot water schedule automatically.
Turn power off to your home
Some people prefer to turn off power to their home when they're going to be away for a long time. If you do this with a Nest thermostat there are some things to keep in mind:
Your Nest thermostat won’t be able to charge its battery when power to your home is off. It will eventually shut down and won't be able to control your system. When it shuts down it will also appear offline in the Nest app.
When power is turned on again, your Nest thermostat will probably need to recharge before it automatically turns on. You’ll see a blinking red light on your Nest thermostat while it charges its battery.
Depending on how low the battery charge is, charging can take up to 3 hours. But you can speed up charging with a USB cable:
Pull off your thermostat's display.
Connect a USB cable to the port on the back of the display and plug it into a wall charger.
Note: You'll need either a mini or micro USB cable depending on your thermostat model.
The thermostat display will turn on and show you a message to connect it to the base.
Reconnect the display to the thermostat base. Make sure you press firmly until you hear it click into place.