Nest Eco temperatures explained
Eco temperatures are a pair of energy-saving limits on a Google Nest thermostat: a "Heat to" floor and a "Cool to" ceiling. While the thermostat shows "Eco", it only heats if the house drops below the floor and only cools if it climbs above the ceiling. Google allows 40 to 70°F for heating and 76 to 90°F for cooling.
What do Eco temperatures actually control?
They are two limits, not a single target. Google calls them "Heat to" and "Cool to". When the thermostat is in Eco, it leaves your system off as long as the house stays between them. Google's description: if your home gets colder than the "Heat to" temperature, the thermostat turns on heating, and if it gets hotter than the "Cool to" temperature, it turns on cooling.
Which limits you see depends on your system. On the Nest Learning Thermostat (3rd gen or earlier) and the Nest Thermostat E, "Heat to" shows up if the thermostat controls heating and "Cool to" if it controls cooling. On the Nest Learning Thermostat (4th gen) and the Nest Thermostat, the Google Home app shows the heating value in orange and the cooling value in blue.
You know Eco is in effect when the word "Eco" appears on the thermostat and in the app. Google says this happens in three ways: the thermostat senses nobody is home, you set your home to Away in the app, or you choose Eco yourself.
What values can you choose?
Google publishes the ranges, and they are the same for every Nest model it covers on its Eco page:
| Setting | Lowest(°F) | Highest(°F) | Can be set to Off |
|---|---|---|---|
| "Heat to" (heating) | 40 | 70 | Yes |
| "Cool to" (cooling) | 76 | 90 | Yes |
Google does not state a factory default for either limit, so check what your thermostat is set to rather than assuming.
Setting a limit to Off is different from a very wide range. Google says that with Off, the thermostat will not turn on heating or cooling in Eco at all, unless the home reaches its Safety Temperature. A fan schedule keeps running either way.
How do you pick a sensible Eco temperature?
Google suggests starting from the temperature you used to set when leaving the house, then going a little lower for heating or a little higher for cooling. Its worked example is a heating-only home kept at 70°F. If the house is well insulated and heats quickly, Google suggests something like 56°F. If it is poorly insulated and heats slowly, 62°F lets it get back to 70°F sooner, with smaller savings.
The tradeoff is recovery time. The further the Eco limit sits from your normal setpoint, the longer the house takes to come back when Eco ends. On the Nest Learning Thermostat (4th gen), Adaptive Eco handles this for you: Google says it adjusts the Eco preset so the home can return to your Comfort temperature within one hour. When it is on, the Home app shows "Adaptive Eco" as the status.
The green Nest Leaf appears when you choose a value Google considers energy saving. Google calls it a guide only.
Where do you change Eco temperatures?
The path depends on the model and the app:
| Thermostat and app | Path |
|---|---|
| Learning Thermostat (4th gen) and Nest Thermostat, Google Home app | Favorites or Devices > Climate > your thermostat > Settings > Temperature presets > Eco, then plus or minus |
| Learning Thermostat (3rd gen or earlier) and Thermostat E, Google Home app | Favorites or Devices > Climate > your thermostat > Settings > Eco Temperatures, then plus or minus |
| Nest app | Your thermostat > Settings (top right) > Eco Temperatures, then drag the slider |
| Learning Thermostat (3rd gen) and Thermostat E, on the device | Press the ring > Quick View > Settings > Eco, choose "Heat to" or "Cool to", turn the ring, press to set |
How long does Eco stay on once it starts?
That depends on how it started and which model you have. This is where most confusion comes from.
- Automatic Eco, any model. When the thermostat switched to Eco because everyone left, it goes back to your normal temperatures when someone comes home. Changing the temperature in the Nest or Google Home app also ends it.
- Manual Eco on the Learning Thermostat (3rd gen or earlier) and Thermostat E. It stays in Eco even when someone comes home, and Google says the schedule is ignored until you switch the mode back to heating or cooling yourself.
- Manual Eco on the Nest Thermostat (2020). It ends at the next scheduled temperature change. To keep it longer you can hold Eco for up to 24 hours.
- Learning Thermostat (4th gen). Use Hold, choose Eco, pick an end time and tap Start hold. The app shows "Eco hold" while it runs.
Two side effects of choosing Eco by hand: if you have several thermostats, each one has to be switched separately, and a manual Eco does not change your home between Home and Away, so other Nest devices such as cameras are not affected.
Does Eco interact with the schedule or learning?
Yes. Automatic Eco sits on top of the schedule. Google notes that even after you turn off Auto-Schedule or Smart Schedule, a thermostat with presence-based automations or Home/Away Assist can still switch to Eco when it senses everyone has left. If Eco is showing up when you do not expect it, see Nest Eco mode turns on by itself. How a Nest builds its schedule in the first place is covered in Nest Auto-Schedule, and the general idea of location-based switching is in thermostat geofencing.
Other brands have their own version of this setting with different rules. The Eco vs Away comparison puts Nest Eco next to ecobee and Honeywell Home Away modes. For more Nest settings, see the Google Nest hub.
Frequently asked questions
- What is a good Eco temperature for heating on a Nest?
- Google does not give one number. Its example is a heating-only home kept at 70°F: in a well-insulated house that heats quickly you might pick 56°F, and in a drafty house that heats slowly you might pick 62°F so it recovers sooner. Anything from 40 to 70°F is allowed.
- Can I turn Eco heating or cooling off completely?
- Yes. "Heat to" and "Cool to" each have an Off choice. With Off, the thermostat will not heat or cool while in Eco unless the house reaches the Safety Temperature. A fan schedule, if you have one, still runs.
- Why does my Nest leave Eco by itself?
- It depends on the model and how Eco started. The Nest Thermostat (2020) leaves a manual Eco at the next scheduled temperature change. On any model, automatic Eco ends when someone comes home or when you change the temperature in the Nest or Google Home app.
- What does the green leaf mean when I set Eco temperatures?
- Google says the Nest Leaf appears when you pick a temperature that can help save energy. It is only a guide. You may still save energy with a setting that does not show the Leaf.