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Room sensors and smart home platforms
Updated
A thermostat only knows the temperature of the hallway it hangs in. A wireless room sensor lets it heat or cool to the bedroom instead. Two picks here include a sensor. Two brands' cheaper models are left off their own sensor lists, and that is easy to miss on a listing.
Sensors by pick
| Pick | Sensor support |
|---|---|
| ecobee Smart Thermostat Premium | One SmartSensor included. ecobee says its sensors read temperature and occupancy, use 915 MHz radio, reach up to 45 feet, and run about a year on a CR2032 coin cell. |
| Google Nest Learning Thermostat (4th gen) | One Nest Temperature Sensor (2nd gen) included. Google says range is about 50 feet over Bluetooth Low Energy, with up to 6 sensors per thermostat. |
| Google Nest Thermostat | Google's sensor page lists the Learning Thermostat (3rd and 4th gen) and the Thermostat E. This model is not on it. |
| ecobee Smart Thermostat Essential | Unclear. The Amazon listing says you can add a SmartSensor, sold separately. ecobee's Room Sensor FAQ says its Room Sensors are not compatible with the Essential. Ask ecobee before you buy sensors for it. |
| Sensi Smart Thermostat ST55 | Sensi says its wireless room sensors work with the Sensi Touch 2 only. |
| Amazon Smart Thermostat | No sensor of its own. The listing says it can use temperature readings from select Alexa devices. |
- ecobee sensor45 feet
- Nest Temperature Sensor50 feet
Wired outdoor or remote sensors from an old thermostat do not carry over. Sensi and Google both say to leave those wires off.
Power matters here too
Google says a Nest that is not getting enough power turns features off, and it lists the remote sensor, Matter support and occupancy detection among them. If sensors or Matter are why you are buying, plan on a C wire or the Power Connector so those features stay on. Sensi has a similar rule: HomeKit needs a C wire.
Platforms, from the listings
| Pick | Works with |
|---|---|
| ecobee Smart Thermostat Premium | HomeKit, Alexa, Google |
| ecobee Smart Thermostat Essential | HomeKit, Alexa, Google |
| Google Nest Learning Thermostat (4th gen) | Google, Alexa, Siri, Matter |
| Google Nest Thermostat | Google, Matter |
| Sensi Smart Thermostat ST55 | Alexa, HomeKit, Google, SmartThings |
| Amazon Smart Thermostat | Alexa only |
| Mysa Smart Thermostat V2 for Baseboards | HomeKit, Alexa, Google |
The Amazon Smart Thermostat has no microphone. The listing says voice control needs a separate Alexa device. The ecobee Premium has a speaker with Alexa built in, and the listing says Siri needs an Apple home hub.
What needs a subscription
Scheduling, remote control and sensors did not show a subscription on any listing we read. One feature did: the ecobee Premium listing says listening for smoke alarm sounds requires an ecobee Smart Security subscription. The thermostat itself does not need it.
Tick your own wires in the wire checker, or compare all seven picks on the roundup page.