On May 7th Google announced they are absorbing their Nest brand. One of the side effects will be the end of developer API access to Nest products.

I bought a Nest thermostat 6 years ago, before Google bought Nest. For quite a few years Nest has operated relatively independently, and I have been able to integrate the thermostat with iOS using homebridge. That seems to be a dead end this summer, so I am looking for a replacement.

Considerations

There are many use cases that people have for smart thermostats, ranging from different types of heating and cooling to varied occupancy programs to integrations with other smart home products. I have combed some other thermostat reviews (in last section below) for the differentiating factors.

Common “C” Wire

Some thermostats require additional power to run, and a third wire running from your equipment to your thermostat mount is mandatory. Not everybody has this wire, and running the wire could be an expensive installation. Some thermostat kits contain a bridge device to run more power over the two wires, meaning you don’t need a “C” wire.

Heating Support

Do you use forced air? Heat pumps? Radiators? Baseboard heaters? Geothermal? Multi-stage heating? Is your heating method supported by your thermostat? There are options available for nearly everything, but most thermostats just cover the most common heating methods.

Humidifier/Dehumidifier/Ventilator

Additional wires are needed to run a Humidifier, Dehumidifier, or Ventilator. Lower-priced thermostats may not support these and you would then have to use an external controller.

Air Conditioning

Like a Humidifier/Dehumidifier, more wires are required. Most devices support cooling, and some support multi-stage cooling.

Furnace Fan

Some furnaces have a fan that can be run separate from heating, should you want to circulate air without heating/cooling. Usually requires additional wire.

Battery Operation

Can run on batteries in addition or separately from the equipment wires.

HomeKit Compatible (or other platforms)

Is the thermostat natively compatible with Apple HomeKit? This means that a “bridge” device is not required to enable support, and that the device can be added to HomeKit using the native iOS Home app.

Alternatively, you may want to make sure it integrates with Amazon Alexa, Microsoft Cortana, IFTTT, or a self-hosted solution such as Home Assistant. Maybe you even want to run Google Home without Nest (perhaps to limit Google’s data collection?).

External Sensors

Does the thermostat include or support external temperature sensors, so you can heat/cool other rooms? Sensors should be cheaper than buying a second thermostat.

Filter Change Reminders

Can you set the app or device to remind you to change your air filter? Is the reminder adjusted based on usage?

“Learning” Schedule

If you adjust the thermostat manually, will the thermostat adjust its default schedule? Is this mode targeted for 9-5 workers only?

UI Quality

Is the interface awkward to use? Do buttons sometimes fail to work? Does the thermostat display anything when idle, or have a blank screen?

Smart Speaker

Is the thermostat integrated with a smart speaker/microphone system, like Google Home or Amazon Alexa? You may even be looking for a device that specifically does not do this, or at least lets you disable the “feature.”

Out-of-home Control

Does the thermostat have cloud integration so you can remotely control it outside your home Wi-Fi?

Energy Usage Reports

Is there data collection to tell you how much you used your heating/cooling? Is the data in an open format that you can download?

MSRP and Rebates

The cost of the device may vary considerably depending on where in the world you live. A device that might be 30% cheaper than the competition may be the same price in your country; in that case, which one you should buy may be different. Your locality may also offer rebates to discount certain brands for an energy savings program.

Thermostats Overview

Below is a list of some of the most common “smart” thermostats. The items should all have Wi-Fi connections, and support control via cloud, mobile app, or platform (HomeKit, etc).

The “Best” thermostat is subjective based on your needs. I hope there is enough information below to help you narrow down your own search.


Honeywell T9 Smart Thermostat

Honeywell T9 Smart Thermostat

Product Page.

May include a remote sensor.

Requires “C” Wire ❗️Yes, but includes adapter
Forced Air Heating ✅Yes
Heat Pump ✅Yes
Electric Baseboard ❌No
Humidifier/Dehumidifier ❌No
Air Conditioning ✅Yes
Manual Fan Control ✅Yes
Batteries ❌No
Apple HomeKit ❗️Coming 2019
External Sensors ✅Up to 20*
Z-Wave ❌No
Filter Reminders ✅Yes
“Learning” Schedule ✅Yes
Smart Speaker ❌No
Energy Usage Reports
MSRP (USD) $199.99

* No support for “S” terminal sensors.


Honeywell T10 Pro Smart Thermostat

Honeywell T10 Smart Thermostat

Product Page

Compared to the T9, the T10 supports humidifiers, dehumidifiers, and ventilators. It appears to be visually identical to the T9, so I have re-used its product image.

Requires “C” Wire ❗️Yes, but includes adapter
Forced Air Heating ✅Yes
Heat Pump ✅Yes
Electric Baseboard ❌No
Humidifier/Dehumidifier ✅Yes
Air Conditioning ✅Yes
Manual Fan Control ✅Yes
Batteries ❌No
Apple HomeKit ❌No
External Sensors ✅Up to 20*
Z-Wave ❌No
Filter Reminders ✅Yes
“Learning” Schedule ✅Yes
Smart Speaker ❌No
Energy Usage Reports
MSRP (USD) Pro Installers Only

* No support for “S” terminal sensors.


Honeywell T5+ Smart Thermostat

Honeywell T5+ Smart Thermostat

Product Page

Requires “C” Wire ❗️Yes, but includes adapter
Forced Air Heating ✅Yes
Heat Pump ✅Yes
Electric Baseboard ❌No
Humidifier/Dehumidifier ❌No
Air Conditioning ✅Yes
Manual Fan Control ✅Yes
Batteries ❌No
Apple HomeKit ✅Yes
External Sensors ❌No
Z-Wave ❌No
Filter Reminders ✅Yes
“Learning” Schedule ✅Yes
Smart Speaker ❌No
Energy Usage Reports
MSRP (USD) $149.99

Honeywell T6 Pro Smart Thermostat

Honeywell T6 Smart Thermostat

Product Page

Requires “C” Wire 👎Yes
Forced Air Heating ✅Yes
Heat Pump ✅Yes
Electric Baseboard ❌No
Humidifier/Dehumidifier ❌No
Air Conditioning ✅Yes
Manual Fan Control ✅Yes
Batteries ❌No
Apple HomeKit ✅Yes
External Sensors ✅Yes*
Z-Wave ✅Yes
Filter Reminders ✅Yes
“Learning” Schedule ✅Yes
Smart Speaker ❌No
Energy Usage Reports
MSRP (USD) Pro Installers Only

* “S” terminal sensors only.


Honeywell Round Smart Thermostat (2nd Generation)

Honeywell Round Smart Thermostat

Product Page

May have had its name changed from “Lyric Round”.

Requires “C” Wire 👎Yes*
Forced Air Heating ✅Yes
Heat Pump ✅Yes
Electric Baseboard ❌No
Humidifier/Dehumidifier ✅Yes
Air Conditioning ✅Yes
Manual Fan Control ✅Yes
Batteries ✅Yes
Apple HomeKit ✅Yes
External Sensors ❌No
Z-Wave ❌No
Filter Reminders ✅Yes
“Learning” Schedule ✅Yes
Smart Speaker ❌No
Energy Usage Reports
MSRP (USD) $249.99

* “C” wire is only needed for HomeKit support


Ecobee3

Ecobee3 Thermostat

Product Page

Compared to the Ecobee3 lite, this one supports humidifiers/dehumidifiers.

May include a remote temperature sensor. Appears to be discontinued, and superceded by the Ecobee4. Can integrate with Alexa, Cortana, HomeKit, IFTTT, Keen Home, SmartThings, WINK, and Yonomi.

Uses a cloud API; there is no local network API access.

Requires “C” Wire ❗️Yes, but includes adapter
Forced Air Heating ✅Yes
Heat Pump ✅Yes
Electric Baseboard ❌No
Humidifier/Dehumidifier ✅Yes
Air Conditioning ✅Yes
Manual Fan Control ✅Yes
Batteries ❌No
Apple HomeKit ✅Yes
External Sensors ✅Yes and API
Z-Wave ❌No
Filter Reminders ✅Yes
“Learning” Schedule ✅Yes
Smart Speaker ❌No
Energy Usage Reports ✅Yes
MSRP (USD) $199.00

Ecobee3 Lite

Ecobee3 Lite Thermostat

Product Page

Remote temperature sensors sold separately. Can integrate with Alexa, Cortana, HomeKit, IFTTT, Keen Home, SmartThings, WINK, and Yonomi.

Uses a cloud API; there is no local network API access.

Requires “C” Wire ❗️Yes, but includes adapter
Forced Air Heating ✅Yes
Heat Pump ✅Yes
Electric Baseboard ❌No
Humidifier/Dehumidifier ❌No
Air Conditioning ✅Yes
Manual Fan Control ✅Yes
Batteries ❌No
Apple HomeKit ✅Yes
External Sensors ✅Yes and API
Z-Wave ❌No
Filter Reminders ✅Yes
“Learning” Schedule ✅Yes
Smart Speaker ❌No
Energy Usage Reports ✅Yes
MSRP (USD) $169.00

Ecobee4

Ecobee4 Thermostat

Product Page

The only thermostat in the list to have a microphone/speaker for Amazon Alexa. May include a remote temperature sensor. Can integrate with Alexa, Cortana, HomeKit, IFTTT, Keen Home, SmartThings, WINK, and Yonomi.

Uses a cloud API; there is no local network API access.

Requires “C” Wire ❗️Yes, but includes adapter
Forced Air Heating ✅Yes
Heat Pump ✅Yes
Electric Baseboard ❌No
Humidifier/Dehumidifier ✅Yes
Air Conditioning ✅Yes
Manual Fan Control ✅Yes
Batteries ❌No
Apple HomeKit ✅Yes
External Sensors ✅Yes and API
Z-Wave ❌No
Filter Reminders ✅Yes
“Learning” Schedule ✅Yes
Smart Speaker ✅Yes, Amazon Alexa
Energy Usage Reports ✅Yes
MSRP (USD) $199.00

Sensi Touch

Sensi Touch Thermostat

Product Page

Requires “C” Wire 👎Yes
Forced Air Heating ✅Yes
Heat Pump ✅Yes
Electric Baseboard
Humidifier/Dehumidifier ❌No
Air Conditioning ✅Yes
Manual Fan Control ✅Yes
Batteries ❌No
Apple HomeKit ✅Yes
External Sensors ❌No
Z-Wave ❌No
Filter Reminders ❌No
“Learning” Schedule ❌No
Smart Speaker ❌No
Energy Usage Reports ✅Yes
MSRP (USD) $169.00

iDevices Thermostat

iDevices Thermostat

Product Page

Requires “C” Wire 👎Yes
Forced Air Heating ✅Yes
Heat Pump ✅Yes
Electric Baseboard
Humidifier/Dehumidifier ❌No
Air Conditioning ✅Yes
Manual Fan Control ✅Yes
Batteries ❌No
Apple HomeKit ✅Yes
External Sensors ❌No
Z-Wave ❌No
Filter Reminders ❌No
“Learning” Schedule ❌No
Smart Speaker ❌No
Energy Usage Reports
MSRP (USD) $99.95

Lux Kono

Lux Kono Thermostat

Product Page

Requires “C” Wire ❗️Yes, but includes adapter
Forced Air Heating ✅Yes
Heat Pump ✅Yes
Electric Baseboard ❌No
Humidifier/Dehumidifier ❌No
Air Conditioning ✅Yes
Manual Fan Control ✅Yes
Batteries ❌No
Apple HomeKit ✅Yes
External Sensors ❌No
Z-Wave ❌No
Filter Reminders ✅Yes
“Learning” Schedule ❌No
Smart Speaker ❌No
Energy Usage Reports ✅Yes
MSRP (USD) $152.99

Hive Active Thermostat

Hive Active Thermostat

Product Page

Requires “C” Wire 👎Yes
Forced Air Heating ✅Yes
Heat Pump ✅Yes
Electric Baseboard ❌No
Humidifier/Dehumidifier ✅Yes
Air Conditioning ✅Yes
Manual Fan Control ✅Yes
Batteries ❌No
Apple HomeKit ❌No
External Sensors ✅Yes
Z-Wave ❌No
Filter Reminders ❌No
“Learning” Schedule ❌No
Smart Speaker ❌No
Energy Usage Reports
MSRP (USD) $169.99

Glas Smart Thermostat

Glas Smart Thermostat

Product Page

Includes Cortana support, as well as air quality monitoring.

Requires “C” Wire ❗️Yes, but includes adapter
Forced Air Heating ✅Yes
Heat Pump ✅Yes
Electric Baseboard
Humidifier/Dehumidifier ✅Yes
Air Conditioning ✅Yes
Manual Fan Control ✅Yes
Batteries ❌No
Apple HomeKit ❌No
External Sensors ❌No
Z-Wave ❌No
Filter Reminders ✅Yes
“Learning” Schedule ✅Yes
Smart Speaker ✅Yes, Cortana
Energy Usage Reports ✅Yes
MSRP (USD) $249.99

Bryant Côr 5C Wi-Fi Thermostat

Bryant Côr 5C Wi-Fi Thermostat

Product Page

Requires “C” Wire 👎Yes
Forced Air Heating ✅Yes
Heat Pump ✅Yes
Electric Baseboard
Humidifier/Dehumidifier ❌No
Air Conditioning ✅Yes
Manual Fan Control ✅Yes
Batteries ❌No
Apple HomeKit ❌No
External Sensors ❌No
Z-Wave ❌No
Filter Reminders ✅Yes
“Learning” Schedule ❌No
Smart Speaker ❌No
Energy Usage Reports ✅Yes
MSRP (USD)

Bryant Côr 7C Wi-Fi Thermostat

Bryant Côr 7C Wi-Fi Thermostat

Product Page

Compared to the 5C model, the 7C can control a humidifier/dehumidifier as well as connect some external sensors.

Requires “C” Wire 👎Yes
Forced Air Heating ✅Yes
Heat Pump ✅Yes
Electric Baseboard
Humidifier/Dehumidifier ✅Yes
Air Conditioning ✅Yes
Manual Fan Control ✅Yes
Batteries ❌No
Apple HomeKit ❌No
External Sensors ✅Yes
Z-Wave ❌No
Filter Reminders ✅Yes
“Learning” Schedule ❌No
Smart Speaker ❌No
Energy Usage Reports ✅Yes
MSRP (USD)

Bryant Housewise Wi-Fi Thermostat

Bryant Housewise Wi-Fi Thermostat

Product Page

Requires “C” Wire 👎Yes
Forced Air Heating ✅Yes
Heat Pump ✅Yes
Electric Baseboard
Humidifier/Dehumidifier ✅Yes
Air Conditioning ✅Yes
Manual Fan Control ✅Yes
Batteries ❌No
Apple HomeKit ✅Yes
External Sensors ❌No
Z-Wave ❌No
Filter Reminders ✅Yes
“Learning” Schedule ❌No
Smart Speaker ❌No
Energy Usage Reports ✅Yes
MSRP (USD)

Tado Smart Thermostat (Starter Kit V3+)

Tado Smart Thermostat

Product Page

Only available in some countries (not including Canada). They also manufacture a smart thermostat for controlling radiators, as well as an Air Conditioner controller. An extension kit (sold separately) can be used to place the thermostat without a direct connection to your equipment.

Compatible with Amazon Alexa, Apple HomeKit, Google Home, IFTTT.

Requires “C” Wire
Forced Air Heating ✅Yes
Heat Pump ✅Yes
Electric Baseboard ✅Yes
Humidifier/Dehumidifier
Air Conditioning ❌No
Manual Fan Control
Batteries ❌No
Apple HomeKit ✅Yes
External Sensors ❌No
Z-Wave ❌No
Filter Reminders
“Learning” Schedule ✅Yes
Smart Speaker ❌No
Energy Usage Reports ✅Yes
MSRP (USD)

Other Reviews