Top 7 Best Smart Thermostats for HomeKit and Apple Siri

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Apple gives us some of the best designed products, but thanks to its relatively closed ecosystem, not all smart thermostats are compatible. Not to worry though. 

I have 7 great options to help you find a smart thermostat for HomeKit and Apple Siri. 

If you’re in a hurry, here’re the top smart thermostats for HomeKit and Siri, Apple’s voice assistant.

It’s a sweep by ecobee smart thermostats as they play well with Apple and provide smart features at a great price. If you want more detailed reviews of the ecobee lineup, read the full comparison of ecobee thermostats

Below the list of the top 7 best smart thermostats for HomeKit is also an overview of criteria to look out for when choosing a Smart Thermostat for HomeKit and Siri. 

1. Best Overall – ecobee SmartThermostat

Ecobee SmartThermostat Features and Benefits

The SmartThermostat (aka ecobee5) is the smartest of the ecobee thermostat lineup and is certified as fully compliant with the Apple HomeKit and Siri system.

It has wireless compatibility with 2.4GHz WiFI, 5GHz WiFi, and Bluetooth. You won’t need to worry about connectivity issues with your home WiFi router. 

The thermostat itself has a sleek rectangular design in the color black, featuring a responsive, glass touchscreen that gives you access to all the features. 

The mobile app has the same design interface as the touchscreen, so there’s no need to learn how to navigate the app. That’ll save you a lot of time from having to learn two different ways of controlling the thermostat. 

The setup is easy and pairing it with HomeKit is straightforward. Once set up, the thermostat can be voice controlled using any device that supports Siri. 

A quick note though, if you have a heating system that doesn’t have a C-Wire, then an adapter is required for the unit to power on and function.

This model also comes with Amazon Alexa and a speaker pre-installed, so your thermostat can also play your favorite tunes.

The thermostat comes supplied with one of ecobee’s SmartSensors that’ll sense room occupancy and adjust the temperature in rooms for your comfort. 

Ecobee’s NEW SmartThermostat is Faster, Louder, and Better with Alexa

Ecobee SmartThermostat Cons

ecobee is not compatible with Zigbee or Z-wave wireless connectivity in their devices.

Some people may not be comfortable wiring in the adapter that is required if no C-Wire is present in their heating system. But there are many professionals who can install it for you.


2. Best Value – ecobee4 Smart Thermostat

ecobee4 Smart Thermostat Features and Benefits

The ecobee4 has Alexa built-in and is also designed to directly work with Apple HomeKit. 

Like others in the ecobee range it’s controlled through a touchscreen interface and an app that offers an identical interface.

The ecobee4 has less wireless connectivity options than the top-of-the-line SmartThermostat, supporting only 2.4GHz Wi-Fi. 

The touchscreen itself is plastic, unlike the SmartThermostat’s glass screen, but it’s still a responsive screen, nonetheless.

Setup is straightforward, but as with all ecobee devices, an adapter must be installed for it to function on systems lacking a C-Wire. 

The ecobee4 ships with a Room Sensor (not a SmartSensor, which is the newer sensor model). However, it’s fully compatible with the SmartSensor and can support up to 32 sensors.

The major difference between the ecobee4 and the SmartThermostat is the lack of Bluetooth wireless and less Alexa features.

A built-in speaker means that as well as controlling your home’s heating system, it can also function as an entertainment and news source. 

ecobee4 Cons

A nice mid-priced thermostat that is slightly let down by the omission of Bluetooth. 

Also, to use it to control multiple zones, a further purchase of SmartSensors will be required as the Room Sensor that comes packaged does not support multi-zones.

3. Best Budget Friendly – ecobee3 Lite Smart Thermostat

ecobee3 Lite Smart Thermostat Features and Benefits 

This is the budget friendly ecobee thermostat, but if you’re looking for an entry level purchase, then this one could be for you. 

The ecobee3 Lite doesn’t come with built-in Alexa, but it’s fully compatible with HomeKit. That’ll allow voice control through Siri, much like with Amazon Alexa and Google Assistant.

The only wireless protocol it’s compatible with is the common 2.4GHz Wi-Fi. There’s no Bluetooth connectivity either.

Although it doesn’t ship with any motion sensors, it’s fully compatible with the range of sensors, SmartSensors and the previous generation Room Sensor. It can still support up to 32 SmartSensors, like the other thermostats.

The set up procedures and interfaces are identical to the other ecobee models and set up normally takes less than an hour. But like the others, an adapter will be needed if you don’t have a C-Wire.

ecobee3 Lite Smart Thermostat Cons

A lack of included sensors and wireless connectivity is always disappointing, but at the end of the day it’s a budget-friendly thermostat. It also lacks an occupancy sensor, although this issue can be fixed with the addition of a SmartSensor on Amazon.

4. Google Nest Learning Thermostat

Google Nest Learning Thermostat Features and Benefits

The Nest Learning Thermostat supports 2.4GHz and 5GHz Wi-Fi, the Weave 802.15.4 protocol, and Bluetooth Low Energy connectivity. 

The Nest Learning Thermostat isn’t directly compatible with Apple HomeKit but can be configured to work within the system by using an additional hub such as the Starling Home Hub in combination with the Homebridge plugin.

We still include it in this list as it is such a powerful device that if you are willing to go that extra mile it is one of the best on the market. Setting it up through a third-party ‘middleman hub’ does add an extra step to a set up routine that is otherwise painless. 

Another benefit is the Nest learning thermostat’s ability to function without a C-Wire or any need for adapters on systems lacking this wire.

The Learning system that is referred to in the name refers to the Nest system’s smart configuration. 

It starts with a baseline schedule and learns your daily habits to adjust the temperature for you comfort. 

The thermostat itself does not feature a touchscreen, instead it relies on a rotating dial to adjust the temperature and cycle through the available options. With the dial also acting as a switch to select the options.

Google Nest Learning Thermostat Cons

Having to incorporate an intermediary hub is a definite minus with this thermostat. It would also be nice if it shipped with a sensor included.

5. Honeywell Home T5 Smart Thermostat

Honeywell Home Lyric T5 Features and Benefits

Before you look at this budget option, this thermostat will not work with homes that don’t use a C-Wire.

The Honeywell Home lineup only supports 2.4GHz Wi-Fi, but that’s the most common WiFi protocol, so the majority of routers should be compatible. 

Apart from that this thermostat is fully compliant with Apple HomeKit and has one of the easiest setups on the market.

The thermostat is controlled by use of a touchscreen and an accompanying app and when configured to work with HomeKit, you can use Siri for voice control.

Although it doesn’t support any sensors it can still be used to control multiple zones by using geofencing that relies on the location of your phone.

It also boasts an adaptive system that learns to adjust heating timings based on how long your home takes to heat or cool.

Honeywell Lyric T5 Thermostat Demo and Review

Lyric T5 Cons

This budget choice offers full HomeKit compatibility, but the T5 falls short in a couple areas. 

The first being a lack of support for HVAC systems that don’t use a C-Wire. The second con is it doesn’t support remote sensors.  

6. Honeywell Lyric T6 Pro

Honeywell T6 Pro Features and Benefits

The Honeywell T6 is a more advanced thermostat than the T5. It boasts all the same features as the T5, but it also offers support for remote sensors. That makes it more suitable for larger homes, while still affordable. 

Like the T5, the T6 supports 2.4GHz Wi-Fi.

The T6 is HomeKit compatible and for HVAC systems with a C-Wire the setup can be completed in around 30-60 minutes. 

Same as the T5, the T6 thermostat will not function without a C-Wire.

Design-wise it looks similar to the T5, offers touchscreen control and the usual mobile app. 

Sensor support gives it improved multi zone support too.

Honeywell T6 Pro Cons

Lack of support for heating systems without a C-Wire and no ability to monitor humidity.

7. Emerson Sensi Touch Smart Thermostat

Emerson Sensi Touch Smart Thermostat Features and Benefits

Emerson is not amongst the most well-known brands, but they do have a proven track record. It was also named as the Best Smart Thermostat by USA Today in 2018.

Another thermostat that falls within the budget range, the Emerson Sensi Touch thermostat is a touchscreen and app-controlled thermostat that is fully compatible with Apple HomeKit. 

Setup is easy and can be set up within 30 minutes and is compatible with 2.4GHz Wi-Fi. A C-Wire is required for this thermostat as well.

It lacks support for remote sensors, which means it doesn’t have multi zone features.

Emerson Sensi Touch Cons

A lack of sensor support means that Multizone is not supported, the design is rather old-fashioned.

Basic Compatibility Requirements for Apple HomeKit and Siri

Apple has a checkered history when it comes to compatibility with non-Apple smart home devices due to their closed ecosystem for their devices. Part of the reason for that is Apple trying to maintain a high level of quality for their devices, platforms, and partners. 

Any device that wants to work with Apple HomeKit must follow the strict Apple protocols to be certified as Apple-compatible devices. Once approved, third-party smart home devices are designed according to Apple’s stringent protocols to integrate easily.

When looking for compatible devices, look for the “Works with Apple HomeKit” sticker. If you don’t see that sticker, you may want to avoid the device. 

Another requirement is that you must possess an iPhone, iPad, AppleTV, or the HomePod/HomePod Mini smart speakers to use Apple’s system. If you don’t already have one, then factor this into the cost.

Smart Thermostats for HomeKit Final Thoughts

The best overall smart thermostat for HomeKit and Siri is the ecobee SmartThermostat. The range of features and ease of use is the standard that the rest of the industry is striving for. 

For the best value and bang for buck, the ecobee4 offers a great combination of features at a good price. 

The budget friendly thermostat is the ecobee3 Lite for those looking for one that’s easier on the wallet. 

Both the ecobee3 Lite and the ecobee4 have the same seamless setup and with the addition of SmartSensors, they can offer just about the same functionality as the SmartThermostat.

For other top smart thermostats, check these out:

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Written by:

Greg Randall
Greg Randall is deeply immersed in Smart Home Technology, with years of experience in home automation, from smart displays to TVs. He enjoys sharing his passion and knowledge with like-minded enthusiasts. Beyond smart homes, Greg loves snowboarding and exploring new culinary scenes with friends, bringing a zest for adventure and fine dining to his tech-savvy lifestyle.