Intelligent Comfort: A Smart Thermostat Buying Guide
When it comes to keeping warm in the winter, knowing which products are designed with your comfort in mind can make all the difference.
But with all the options on the market, which one to choose? Below, we’ve parsed out some of the features of top-rated thermostats to help you when it comes to deciding which model would be ideal for you and your family.
Before You Buy
There are a few important factors to consider before you choose a thermostat, such as the type of system you have and whether or not you will need a C-wire (common wire). Some thermostats only work with gas or electric systems, while others are more versatile and control a heat pump and air conditioning, as well as offering dual-fuel support.
Whether you will need a low-voltage or line-voltage thermostat depends on the type of system you have. Low-voltage thermostats tend to be more efficient and accurate, work with central heating and air systems, and generally offer programmable options. Single-heating systems, such as radiator valves and baseboard heaters, are recommended to use with a line-voltage thermostat. The smart thermostats featured in the guide below work with low-voltage systems only.
The C-wire connects directly to the smart thermostat. Some thermostats require the C-wire, which may or may not already be installed in your system. Ecobee products ship with an adapter, which you can install if your system lacks a C-wire. While most smart thermostats come with self-installation manuals, if your wiring requires adjustment, you may want to call a professional to install the system for you.
Nest Thermostat E
Like most smart thermostats, the Nest Thermostat E allows you to control the temperature from an app, which also tracks your energy use over time. Nest’s independent studies have shown a 10–12% average savings on heating and 15% on cooling among its client base. That’s largely due to the fact that you aren’t paying to heat or cool an empty house; Nest’s Home/Away Assist feature automatically adjusts the temperature after you leave.
C-wire required
Because Nest thermostats use very little power, they don’t typically need a C-wire. If you already have one, the installation guide will tell you to connect it. Nest offers an online compatibility checker that takes you step-by-step through a process that will determine if you need to connect the wire or not.
Cost Savings
10–12% average savings on heating and 15% on cooling
Self-installation
Yes
Voice assistant
Compatible with Amazon Echo, Tap, and Dot; Google Home; Homebridge; Fitbit
Compatibility
The Nest Thermostat E works with most 24V heating and cooling systems, including gas, electric, forced air, heat pump, radiant, oil, hot water, solar, and geothermal. Heating and cooling: 1 stage of heating (W1) and cooling (Y1) and a second stage of either heating (W2) or cooling (Y2). Heat pump: with auxiliary and emergency heat (O/B, AUX). Fan (G). Power (C, Rh or Rc).
Connectivity requirements
Wi-Fi internet connection, Phone or tablet running iOS or Android, & Nest app. Wi-Fi connection: 802.11b/g/n 2.4GHz, 802.11a/n 5GHz; Wireless interconnect: 802.15.4 @ 2.4GHz, Bluetooth Low Energy.
Bandwidth requirements
~50MB/week upload and 50MB/week download
Certifications
UL 60730-1, Standard for Safety Automatic Controls; UL 60730-2-9, Particular Requirements for Temperature Sensing Controls; ENERGY STAR®
Warranty
1-year
Power consumption
Less than 1 kWh/month
Other features
- Auto-Schedule
- Home/Away Assist
- Energy History
- Home Report
- Nest Leaf
- Nest app
- Airwave
- System Match: Early-On, Heat Pump Balance, True Radiant
- Time-to-Temperature
- Weather aware
- Advanced Fan Control
- Sunblock
- Cool to Dry
- Thermostat Lock
- Software updates over Wi-Fi
- Safety Temperature Alert
- Furnace Heads-Up
- Filter Reminder
- System Test
Nest Learning Thermostat, 3rd Gen.
The Nest Learning Thermostat’s Auto-Schedule feature learns your schedule and then sets one on its own. Like the Nest Thermostat E, the Nest Learning Thermostat adjusts the temperature after you leave so you are not paying to heat or cool empty spaces. Additionally, The Nest app allows you to track your energy usage over time and see how much you are using. The Nest Leaf icon is visible when the temperature is saving energy. Like the Nest Thermostat E, a filter reminder appears when it is time to change your filter.
C-wire required
Because Nest thermostats use very little power, they don’t typically need a C-wire. If you already have one, the installation guide will tell you to connect it. Nest offers an online compatibility checker that takes you step-by-step through a process that will help you to determine if you need to connect the wire or not.
Cost savings
10–12% average savings on heating and 15% on cooling
Self-installation
Yes, though Nest recommends professional installation for anyone with dual fuel systems, whole-home humidifiers/dehumidifiers, or multi-speed fans.
Voice assistant
Compatible with Amazon Echo, Tap, and Dot; Google Home; Homebridge; Fitbit
Compatibility
The Nest Learning Thermostat works with 95% of 24V heating and cooling systems, including gas, electric, forced air, heat pump, radiant, oil, hot water, solar and geothermal. Heating: 1, 2, and 3 stages (W1, W2, W3). Cooling: 1 and 2 stages (Y1, Y2). Heat pump: with auxiliary and emergency heat (O/B, AUX, E). Humidifier or dehumidifier (HUM, DEHUM). Fan (G). Power (C, RH, RC).
Connectivity requirements
Wi-Fi connection with internet access; Nest app on phone or tablet with iOS or Android; Latest version of Safari, Chrome, Firefox, or Internet Explorer on Mac OS X v10.9 or later and Windows 7 or later; Free Nest Account.
Bandwidth requirements
Average bandwidth ~50MB/week upload and 50MB/week download
Certifications
UL 873, Temperature-Indicating and -Regulating Equipment; CSA-C22.2 No. 24, Temperature-Indicating and -Regulating Equipment
Warranty
2-year
Power consumption
Less than 1 kWh/month
Other features
- Auto-Schedule
- Home/Away Assist
- Energy History
- Home Report
- Nest Leaf
- Nest app
- Farsight
- Airwave
- System Match: Early-On, Heat Pump Balance, True Radiant
- Time-to-Temperature
- Weather aware
- Advanced Fan Control
- Sunblock
- Cool to Dry
- Thermostat Lock
- Software updates over Wi-Fi
- Safety Temperature Alert
- Furnace Heads-Up
- Filter Reminder
- System Test
- Stainless steel ring
ecobee3 Lite Programmable Thermostat
Like Nest thermostats, the ecobee3 Lite works with room sensors (sold separately) to determine if a room is occupied and to eliminate hot and cold spots. The thermostat is hardwired to ensure a reliable connection. From the app, you can access an installation guide, set temperature controls, and view monthly energy reports, which show usage and offer tips on how you can save more energy. The thermostat works with Android and iOS devices.
C-wire required
Yes
Cost savings
23% annually on heating and cooling
Self-installation
Yes
Voice assistant
Requires an iPhone, iPad, or iPod touch with iOS 9 or later
Compatibility
Gas, oil, electric, dual fuel support; Conventional (2H/2C); Heat Pump (4H/2C); 2-stage auxiliary heat; Humidifier, Dehumidifier, Ventilator, HRV or ERV
Connectivity requirements
Security; Wi-Fi, IEEE 802.11 b/g/n @ 2.4 GHz; Wi-Fi Protected Access (WPA/WPA2) and Wired Equivalent Privacy (WEP); DHCP (dynamic) or static IP addressing; Transport Layer Security (TLS); 915 MHz
Bandwidth requirements
15-20 MB/month
Certifications
ENERGY STAR® certified
Warranty
3-year
Power consumption
~0.0035 kWh/month
Other features
- Works with Room Sensor
- Occupancy detection: sensors
- Sustainability: Recyclable packaging, Mercury-free, Arsenic-free, PVC-free, ROHS compliant
ecobee 4 Smart Thermostat
The included room sensor works with the thermostat to manage hot and cold spots throughout the home and detects when a room is occupied or not. The ecobee4 smart thermostat has a few advantages over the ecobee3 Lite, including built-in Amazon Alexa and far-field voice technology, which allows voice control for your thermostat. The ecobee4 also supports humidifier, dehumidifier, ventilator, ERV, and HRV systems.
C-wire required
Yes
Cost savings
23% annually on heating and cooling
Self-installation
Yes
Voice assistant
Built-in Alexa Voice Service, Built-in microphones, Built-in speaker, Far-field voice recognition, Sensory TrulyHandsfree™ Wake Word engine
Compatibility
Gas, oil, electric, dual fuel support; Conventional (2H/2C); Heat Pump (4H/2C); 2-stage auxiliary heat; Humidifier, Dehumidifier, Ventilator, HRV or ERV
Connectivity requirements
Wi-Fi, IEEE 802.11 b/g/n @ 2.4 GHz; Wi-Fi Protected Access (WPA/WPA2) and Wired Equivalent Privacy (WEP); DHCP (dynamic) or static IP addressing; Transport Layer Security (TLS); 915MHz
Bandwidth requirements
15+ MB/month (dependent on Alexa Voice Service usage)
Certifications
ENERGY STAR® certified
Warranty
3-year
Power consumption
~0.0035 kWh/month
Other features
- Built-in Amazon Alexa
- Far-field voice technology
- Works with Room Sensor
- Occupancy detection: thermostat + sensors
- Sustainability: Recycled packaging, Mercury-free, Arsenic-free, PVC-free, ROHS compliant
Emerson Sensi Touch Wi-Fi Smart Thermostat
The Emerson Sensi Touch thermostat is controlled with an app, which includes a self-installation guide with video tutorials that walk you through set-up. The thermostat works with 95% of HVAC equipment; you can use Emerson’s compatibility checker to make sure your system is a fit.
The Sensi Touch includes an indoor humidity sensor that reads humidity levels throughout your home, and a geofencing feature automatically adjusts temperature settings based on the location of your smart phone.
C-wire required
Yes
Cost savings
23% annually on heating and cooling
Self-installation
Yes
Voice assistant
Apple HomeKit, Google Assistant, Amazon Alexa, Wink
Compatibility
Extensive Compatibility: works with the HVAC equipment found in most homes - all system types require a C-wire.
Connectivity requirements
Wi-Fi 802.11b/g/n @ 2.4 GHz; WPA and WPA 2 encryption methods
Certifications
ENERGY STAR® certified
Warranty
3-year
Power consumption
Information not provided by manufacturer.
Other features
- Geofencing
- Flexible scheduling
- Usage report
- Auto changeover from heat to cool
- Settings lock
- Usage report
