Does the Nest Thermostat replace my programmer, thermostat, or frostat?
A programmer turns your heating system off completely during certain parts of the day or night, which could be a problem if it gets very cold and your home isn’t well insulated. So the Nest Thermostat saves energy like a programmer, keeps you comfortable like a thermostat, and protects your home like a frostat.
Currently, you control the heat in your home with some combination of programmer, thermostat and frostat:
Allows you to see and change the temperature in your home by turning the heat on and off according to the room temperature.
Saves energy by shutting the heat off for hours of the day you’ve scheduled. This is efficient but gives you no way to track or control how cold it gets in your home.
This boiler add-on turns up the heat automatically if there’s a chance your pipes will freeze in severe cold weather.
Programmer off-times save energy, but leave your home unprotected if it gets very cold. Instead, frostats are used to turn on the heat if your pipes are in danger of freezing. But you shouldn’t have to rely on two different devices to manage heat: one that puts your home at risk, one that saves it in an emergency. Your home should never be at risk in the first place.
How does it work?
The Nest Thermostat combines all these capabilities and improves on them. Everything is captured in one schedule, which automatically adapts to your life and can easily be adjusted in one place. After you install your Nest Learning Thermostat, you won’t use your programmer or frostat again.
So with the Nest Thermostat, you can add 9ºC temperatures to your thermostat schedule, rather than scheduling times that the heat will be off with a programmer. A 9º minimum means it’s unlikely that your heating will be on, but the thermostat will turn the heat on if your home gets too cold, which can help protect your pipes.
For example, say the temperature is set to 9º at night, rather than off. In normal weather, your home probably wouldn’t ever get colder than 12º. So with the heat set to 9º, your heating system won’t turn on all night and you’ll save energy. However, if temperatures drop dangerously low, the system will come back on to protect your home and your plumbing. No frostat required.
How do I add these low temperatures to my schedule?
During setup, when you first install your thermostat, Nest will ask you when your programmer scheduled the heat to remain off. Then it will automatically enter 9ºC temperatures during those times.
Your schedule will look simple at first.
Within days, Auto-Schedule will start to learn what temperatures you like and add more temperatures to your schedule.
Are the low temperatures I add during setup part of my regular schedule?
Yes - you have one schedule, which includes the temperatures you add manually and the ones the Nest Thermostat learns automatically.
After installation and setup, it will be time to teach your Nest Thermostat your daily schedule. You do that by adjusting the temperature - down when you leave the house, up when you come home, down when you go to bed. Remember to teach it well - the Nest Thermostat saves the most when it learns good habits from you.
Within a week, the Nest Thermostat learns your schedule. The temperatures you’ve set will appear on the schedule along with the 9º temps you added during setup:
Will Auto-Schedule adjust the temperatures I add during setup?
Auto-Schedule is there to adjust the temperatures in your schedule as your life changes, and that includes the 9ºC temps you added during setup. Of course the Nest Thermostat also pays attention if you change your mind. For example, say you start staying up late with a crying baby. You may not want the boiler to turn off at 10pm anymore. So every time the temperature drops in the evening, you turn up the heat to 19º. If you do this at the same time for a few days, then Auto-Schedule will notice, learn, and adjust the temperatures in your schedule.
In this case, you have to remember to turn the heat down before you go to bed so Auto-Schedule can learn your new routine and start turning it down for you. You can also manually change your schedule to add another 9ºC temperature to a later time:
What happens to my programmer if my heating system is not using it anymore?
Your installer will either disconnect your programmer entirely, or, if it also controls hot water, will disconnect the programmer’s heating channel and leave it set to ALWAYS ON so the Nest Thermostat can manage heat without interference. In this case, your installer will put a sticker on your programmer to remind you not to adjust the heating channel.
Can I turn off my boiler completely?
If you don’t want your Nest Thermostat to heat under any circumstances, set your Safety Temperatures to OFF, then turn the Nest Thermostat off.