Nest Thermostat Keeps Switching to Eco Mode While You Are Home? Stop It for Good

You are sitting at home, perfectly warm an hour ago, when the house starts to feel chilly. You check the thermostat and find it has dropped into Eco mode, with its leaf icon showing and the temperature drifting down, even though nobody has left the building. It feels as if your thermostat has decided you are out and stopped listening.

Nest thermostats switch to Eco temperatures when they think the home is empty, to save energy. The feature is useful when it is right and annoying when it is wrong. Eco is controlled by clear settings: Home and Away routines, presence sensing, phone location, and device sensors. Once you find which signal is misbehaving, you can stop the unwanted switching.

Quick Answer

Your Nest thermostat switches to Eco when Home and Away features think everyone has left. To stop it while you are home, open the Google Home app, check Presence settings, and make sure your phone location is allowed and set to always, your phone is marked as a presence device, and the thermostat’s own motion sensor is enabled. If you do not want automatic switching at all, turn off the Home and Away routine or set Eco temperatures closer to your normal comfort temperatures.

How Nest Decides That You Are Away

The thermostat does not have one simple away switch. It combines signals and acts when they agree that the home is empty.

The Main Signals It Uses

• Phone location: The Google Home app can use your phone’s location to tell when the last household phone leaves a small area around the home, called a geofence, and when it returns.
• Device motion sensors: The thermostat itself, and some connected sensors or speakers in certain setups, notice movement in the home.
• Learned patterns: Older Nest models learned your routine over time and built an auto-schedule and early away behaviour around it.
• Manual routines: A Home and Away routine in the app can set Eco, or switch the thermostat mode, based on presence changes or times of day.

Eco temperatures are the cooler heating and warmer cooling temperatures used while the thermostat thinks you are away. When presence flips to Away, it moves to those temperatures, and returns to your schedule when it senses you home again. A wrong presence signal is almost always the whole story.

Common Reasons It Thinks an Occupied Home Is Empty

Work through these causes before changing lots of settings. Often one simple fault explains everything.

• Phone location is restricted: If the app only has location access while in use, or battery saving keeps putting the app to sleep, the phone looks as if it has left.
• You left your phone behind: If your phone went out with a partner, or you walked out with a different phone signed into the home, presence can flip.
• Your phone is off or in deep power saving: A dead battery, flight mode, or aggressive battery optimisation can remove your main presence signal for hours.
• The thermostat sees no movement: If you work in a room far from the thermostat, sit still for long periods, or the thermostat is in a quiet hallway, its sensor may report no activity.
• A routine is doing it on purpose: A timed routine, a leftover automation, or another household member’s phone can set Eco without you realising.
• Wi-Fi or internet dropouts: Without a connection, location and presence updates can stall in the wrong state.

Step-by-Step: Fix Presence Sensing in the Google Home App

These steps use current Google Home wording. Menu names move slightly between app versions, but the ideas stay the same. The official steps for your app version are also listed on the official Google Nest support pages for Home and Away and presence sensing, which are worth opening on your phone while you work.

1. Open the Google Home app and go to Settings, then look for Presence sensing or Home and Away settings for your home.
2. Check which phones are listed as presence devices. Make sure your phone is included and your old phones are removed.
3. On your phone, open its system settings for the Google Home app and set location permission to Allow all the time, or Always, not only while using the app.
4. Turn off battery optimisation, or set the app to unrestricted battery use, so Android or iOS does not sleep it in the background.
5. Confirm location services and precise location are on for the phone itself, and that the home address in the app is correct. A wrong address puts the geofence in the wrong place.
6. In presence settings, allow the thermostat and any suitable home devices to contribute their motion sensing to presence detection.
7. Save everything, then test by staying home with your phone in your pocket for an afternoon and watching whether the status stays Home.

Check Other Household Phones Too

Presence is a household decision. Every member’s phone counts. One flatmate whose app is signed out, or who removed location permission after an update, can flip the whole house to Away. Ask every member to confirm they are signed in and check their location setting.

Adjust Eco Temperatures So Mistakes Matter Less

Even with presence working well, set Eco temperatures sensibly. If Eco heating is very low, one wrong Away decision makes the house cold fast. Set it only a few degrees below normal, and a mistake becomes a mild annoyance rather than a freezing evening.

1. On the thermostat or in the app, open Settings and find Eco temperatures.
2. Set the Eco heating temperature to a level you would tolerate for a few hours, rather than the lowest possible number.
3. Set the Eco cooling temperature similarly, a little warmer than normal but not uncomfortable.
4. Check pipes and pets: homes with vulnerable pipework or animals at home should never use extreme Eco settings anyway.

Turn Off Automatic Away Switching Completely

Some households simply prefer full manual control. Shift workers, people who work from home all week, and homes where someone is almost always in often get more comfort from switching the feature off.

1. In the Google Home app, open Automations or Settings and find the Home and Away routine.
2. Turn off the routine actions that set the thermostat to Eco when the home is Away, or disable the routine entirely if you do not use it for lights or other devices.
3. On older Nest app setups, look for Home/Away Assist and switch it off there instead.
4. Check for any separate scheduled routines that set Eco at set times, such as a weekday morning routine built when you used to commute.
5. For a few days, change temperature manually or by schedule only, and confirm Eco never appears on its own.

Behaviour Tips That Help Presence Work Better

If you keep the feature on, small habits help. Keep your phone with you when you go out and leave it on at home. Walk past the thermostat now and then if you work in a back room for long hours. Stable Wi-Fi also matters, because presence updates travel through your connection.

For a tidy wider setup that supports features like presence and routines, follow a clean speaker and device setup order such as the one in our guide to setting up smart speakers and home devices step by step, so every device sits in the right home and account from day one.

Common Mistakes to Avoid

• Only fixing your own phone: One household member with broken location settings can flip the whole home to Away.
• Setting location to while using the app: Presence needs background location. Without Always permission, the system cannot see you leave or arrive properly.
• Extreme Eco temperatures: Very low Eco heating turns a small presence mistake into a cold house and slow recovery.
• Forgetting old routines: A weekday routine from an old job can set Eco at 9 a.m. every day regardless of presence.
• Blaming the thermostat sensor only: In most homes the phone location signal matters more than the wall sensor. Check both.
• Multiple homes in the app: A duplicate home at a slightly wrong address confuses geofencing. Keep one correct home.

Conclusion

When a Nest thermostat slips into Eco mode while you are home, it is acting on a presence signal that says the house is empty. Fix the signals first: Always location for every household phone, unrestricted battery use for the app, the correct home address, and the thermostat sensor allowed to help. Soften the Eco temperatures so an occasional mistake costs little comfort, and turn off Home and Away switching entirely if your household is home most of the time. With those settings settled, Eco becomes a holiday tool you choose, not a surprise that chills your evening.

Frequently Asked Questions

Why does Eco mode turn on at the same time every day?

A fixed time points to a routine or a learned schedule rather than presence. Check Automations in the app for timed routines, and review the thermostat schedule and any learning features for a repeated away pattern.

Does my phone need location on all the time for presence to work?

For phone-based presence, yes. The app needs background, Always location permission and enough battery freedom to update when you cross the home boundary. Without it, the system relies on motion sensors alone, which is less reliable.

Can I keep Eco for holidays but stop it on normal days?

Yes. Turn off the automatic Home and Away routine for daily life, then switch Eco on manually from the app or thermostat when you go away. You keep the holiday savings without daily false alarms.

Why does the thermostat say Away when I am in another room?

Its motion sensor only sees its own area, often a hallway. If nobody passes it for a long time and phone signals are weak or restricted, the home can be marked Away. Fix phone location first, and let other suitable devices help with presence if your setup offers it.

Will turning off Home and Away stop my schedule working?

No. Your normal temperature schedule continues as set. Turning off Home and Away only stops the thermostat from overriding that schedule with Eco temperatures based on presence.