While the now-Google-owned Nest brought the idea of smart home thermostats into the mainstream consciousness, it is by no means the only player in the game — nor was it even the first by a long shot. In fact, the race began back in 2008, when a small startup named ecobee debuted the world’s first Wi-Fi connected smart thermostat. Hence, it’s probably only fitting that the company’s ecobee3 was the first thermostat to join the club when Apple’s HomeKit home automation framework came online. In addition to providing control via HomeKit, ecobee3 has more than a few of its own unique capabilities to recommend it, and like other HomeKit devices we’ve taken a look at recently, was an existing product that added HomeKit capabilities, rather than a new product released specifically for HomeKit.

For many users, there’s value in a thermostat having a certain aesthetic appeal — after all, it often lives in a very prominent place in the home or apartment. The ecobee3 eschews the classic design of T-86 Round that’s inspired other recent smart thermostats, preferring to go for a more clean, modern look. While it’s obviously a matter of taste, we found the ecobee3’s look to be quite appealing.
The ecobee3 package provides two different mounting options for the thermostat, which is designed to be installed into drywall as opposed to an electrical junction box. Users who have a small enough hole for their existing thermostats can use the smaller backplate to mount right onto the wall, while if you have holes or other markings left by your prior thermostat that you want to cover up, a larger round plate is also included.
In our case, despite having a large gaping hole with a light switch junction box where our previous thermostat had been installed, we weren’t really fans of the larger, circular plate option. So we instead drilled a smaller hole to the right of the junction box, mounting the thermostat there, and then filling the light switch sized hole with a Lutron Caséta Pico remote. In the package, ecobee includes almost everything else you need to install the thermostat in most home environments, including drywall mounts and screws and even a built-in level on the backplate — a very nice touch to help you get the orientation right with a minimum of extra effort.
Wiring up the ecobee3 was similarly straightforward from a physical point of view — we particularly liked the use of a spring-clamp block terminal rather than the screw-down style found on most other thermostats, and everything was clearly labelled. ecobee’s website provides detailed instructions on how to wire the thermostat up in just about every possible configuration. Like almost every other electronic thermostat on the market, you’ll need a “C” wire coming from your HVAC system to provide the 24VAC to power the thermostat itself, however ecobee has very smartly included a power extender in the box for situations where three or more wires are running from the HVAC system without a C-wire.
The inclusion of the power extender makes it possible to handle almost every wiring scenario except the most basic situation where only a single pair of two wires is present. Again, though, this problem is not unique to the ecobee3 — the only electronic thermostat we’ve seen that can run on only two wires is the Nest, and it uses a somewhat unorthodox method to accomplish this that can actually damage or at least shorten the life of some furnaces. In this case, we appreciate ecobee going by the book here and they definitely get extra credit for including the power extender in the box. Users who are stuck with only two wires can find several recommendations on ecobee’s web site for dealing with that scenario.
Once the ecobee3 is connected it will power-up and take you through a guided setup process that will try to automatically detect the wires that are connected to your thermostat, giving you the option to correct it if it finds one missing, and then will ask a few additional questions about your system and what type of equipment you have installed, your temperature unit preference, and then ask you to name your thermostat, specify your ideal home temperature during the winter season, and then choose your time zone and connect to your Wi-Fi network. The Wi-Fi network configuration was a particularly interesting step, as it actually sent us to the Wi-Fi configuration in the iOS Settings app, rather than ecobee’s own app, where the ecobee3 appeared under a “Set Up New Device Heading” — a step that takes advantage of a feature in iOS 9 that we weren’t even aware existed prior to this.
Once the Wi-Fi connection has been established, the thermostat screen will direct you to load up the ecobee iOS app to complete the registration process, which involves entering a code displayed on the thermostat screen and then setting up a user account with ecobee. This account is used for remote access to the ecobee3 separate from HomeKit, and ecobee also provides a web portal where you can configure your thermostat settings using any web browser and get intelligent reports on your energy usage and heating system performance — like most smart thermostats, a key selling point of the ecobee3 is that it’s supposed to save you considerable money on heating bills in the long run, so it only makes sense that ecobee wants to provide you with as much of this information as possible. During the account setup process, ecobee will also ask several other relevant questions about your home such as its age, number of rooms and floors, and square footage.
Like other pre-HomeKit accessories we’ve reviewed, all of this initial configuration is specific to the ecobee3, and in fact you can setup and use the thermostat without any requirement that you include it in your HomeKit configuration; it’s a very powerful and feature-rich smart thermostat in its own right. The process of adding the ecobee3 to HomeKit is a separate step, but follows the standard HomeKit setup we’ve come to know by now — a HomeKit code will be displayed on the thermostat screen, which can be scanned into the ecobee3 app, after which the device is paired to HomeKit and assigned to a room. The ecobee3 however takes this one step further, automatically adding itself into the four default HomeKit scenes — Good Morning, I’m Leaving, I’m Home, and Good Night — and creating its own HomeKit scene, Resume Schedule. The settings here can of course be tweaked later, but what ecobee is actually doing here is matching the ecobee3’s three standard comfort settings — Home, Away, and Sleep — to the default HomeKit scenes, rather than simply assigning arbitrary temperatures through HomeKit.
This is where the real power of the ecobee3 comes into play, in fact. In stark contrast to the iDevices Thermostat, which was nothing more than a remotely HomeKit-controllable digital thermostat, the ecobee3 is a smart thermostat in its own right, which uses HomeKit as an extension of its capabilities, rather than the foundation. Even without HomeKit support, the ecobee3 is capable of monitoring and controlling not only temperature but also humidity, as well as following a daily/weekly schedule, being controlled remotely through the ecobee app or web portal, and intelligently detecting when users are at home or away through the use of motion sensors and geofencing. HomeKit adds the ability to check the temperature and make adjustments with Siri voice commands, as well as integrate the thermostat with other HomeKit accessories for the sake of timed schedules, rules, and event triggers, but in reality we found that there’s a lot of value in most of the ecobee3’s own built-in capabilities, and HomeKit just adds to that, rather than replacing it.
Recognizing that most users will likely only ever alternate between a handful of standard temperature settings, ecobee3 uses three pre-defined “comfort” settings — Home, Away, and Sleep. Rather than using arbitrary temperatures in schedules, you specify your preferred temperatures for each of those three modes, and then setup schedules to switch between modes based on the time of day. Up to five more custom comfort settings can also be configured through the web portal if your daily or weekly routine requires more than three settings. The use of these pre-defined comfort modes also allows schedules to be more logically overridden, either manually or automatically. The idea is that it’s easier to say that you’re “Home” during an “Away” period (or vice-versa) without needing to think about what you want to set the temperature to. Multiple vacation schedules can also be configured — several years in advance, even — for those dates and times that you know you’ll be away and therefore want to override the ecobee3’s settings during those time periods.
One of the most interesting key selling points of the ecobee3 is its use of remote sensors. As anybody who has been dealing with thermostats probably already knows — and as ecobee is quick to point out — pretty much every thermostat ever released has suffered from the problem of only being able to monitor the temperature in the place where the thermostat is physically installed, which can often be a drafty hallway or front foyer, rather than a living room or family room. This is definitely a limitation we’ve run into ourselves, and in the past it’s taken a lot of fussing with imperfect workarounds like using Netatmo’s weather station and IFTTT integration to pull temperature readings in from one device and try to adjust space heaters and thermostats appropriately — messy and “hacky” solutions that most non-technical users wouldn’t even think of trying.
The far more elegant approach that ecobee provides to address this problem is to deploy remote sensors that read temperatures in various areas around the house and communicate those temperatures back to the central thermostat. The thermostat can then average the temperatures in various rooms to provide the optimal comfort level. One remote sensor is included in the ecobee3 package; additional sensors are available at a price of $80 for a package of two, and a single ecobee3 thermostat can support up to 32 sensors.
However, ecobee takes this a step further, equipping each of these remote devices with not only temperature and humidity sensors, but also motion sensors. The idea here is simple: while you can read the temperature in any room in the house, it makes no sense for the ecobee3 to factor temperatures into its calculations for rooms that are unoccupied, so if motion has not been detected by a given sensor for at least 30 minutes, that sensor’s temperature readings are ignored for the purposes of ecobee3’s temperature settings. The remote sensors are also used to factor into ecobee3’s smart home/away feature — if motion is detected during a time when you’re supposed to be “Away” the ecobee3 will automatically engage “Home” mode, and vice-versa if no motion is detected for a long enough time period when you’re otherwise supposed to be home (as one would expect, a lack of motion is ignored during a scheduled “Sleep” period, however). Obviously the more strategically you deploy these sensors around your house, the more effectively this feature will work.
Where HomeKit fits into the picture is allowing you to use Siri voice commands to either set aribtrary temperatures (“Set my thermostat to twenty-one degrees”) or change modes (“Enable ecobee3 Home”), as well as querying temperatures from not only the thermostat itself, but also from any one of the sensors, or all of them together (“What is the temperature at home?” will give you a range of all of your temperature readings). The ecobee3 can be included in any HomeKit scene to set arbitrary temperatures, or the pre-defined inclusions can be used to automatically engage the appropriate comfort mode when arriving or leaving home, or going to bed or getting up in the morning. These can be done with Siri voice commands (“Good morning”), or included in other triggers, such as a location rule that triggers the “I’m home” scene when arriving at home. The new “Resume Schedule” scene also allows you to cancel the comfort setting override and return to your normally programmed schedule. Of course, if you prefer to rely solely on the ecobee3’s own home/away schedules and logic, you can simply remove the ecobee3 from each of the default scenes — you’ll still get Siri control and monitoring and the ability to include the ecobee3 in other scenes and triggers, while using the schedule and motion sensors to determine whether anybody is home.
As if that weren’t enough, however, the ecobee3’s sensors offer a really cool additional bonus for HomeKit users: the motion sensors can actually be used as HomeKit triggers. Due to the nature of the ecobee3’s goal to measure occupancy rather than transient motion, the motion sensors don’t operate in an immediately real-time mode, so you won’t be able to setup a rule to reliably have the lights come on the instant you enter a room, nor turn off the instant you leave, but in the same way the ecobee3’s motion sensors are designed to let unoccupied rooms cool down, leveraging them in HomeKit triggers is a really useful way to ensure the lights are turned off when rooms are no longer occupied, saving you on your electricity bill in addition to your heating bill. While the feature isn’t enough by itself to justify an investment in an ecobee3, it’s a really nice bonus, especially with the dearth of these types of sensors available for HomeKit in any other form at this point. The only downside is that the sensors fit into HomeKit in a slightly odd way right now — they form part of the thermostat accessory, and while they can be queried through Siri with separate names, you can’t place them in different HomeKit rooms, as they’re not listed as separate devices. That said, some HomeKit apps, such as Hesperus have dealt with this, presenting the sensors as distinct devices in the HomeKit configuration, and thereby making them easier to find and use in triggers and other rules. It’s not a serious limitation, however, particularly considering that the use of the motion sensors in this way is more of a “bonus” than a core ecobee3 feature; if it’s something you plan on using, we’d just recommend getting the free Hesperus app and you’ll be fine.
The ecobee3 also includes several other really nice smaller touches that are definitely worth mentioning as they add to the overall appeal of the package. The thermostat includes a large, easily readable and responsive touchscreen display, which not only provides access to the usual thermostat settings, but also displays weather information, with conditions and outside temperature available at a glance. The display shows the current indoor and outdoor temperature while in standby mode; walking up to the thermostat will automatically disengage the standby mode to show the thermostat settings, and a more detailed forecast can be pulled up by tapping on the weather button at the bottom of the screen. While seeing the weather is really handy, this information isn’t just for display purposes — the ecobee3 also uses local weather conditions to determine the most optimal way to heat or cool your home while minimizing how long your HVAC system runs for. The ecobee3 uses similar smart algorithms to optimize fan usage, using fans or ventilators on cool summer evenings rather than powering up the air conditioning system, and can monitor and maintain humidity levels appropriately if you have it connected to a dehumidier or air conditioning system, automatically regulating indoor humidity to prevent frost or condensation on windows due to temperature differences.
We’re seriously impressed with what ecobee has done with the ecobee3, and not only is it a very intelligent and capable thermostat by itself, but the remote sensors solve a very real problem for anybody who lives in a medium-to-large house in an area with large seasonal temperature changes. The HomeKit support is well done, and the ability to use the motion detection capabilities of the remote sensors to control other HomeKit devices is also a really great additional bonus. The ecobee3 is very straightforward to install, and the company has done a good job of providing lots of support and guidance in that regard, but it’s still something you’re going to have to be comfortable doing yourself or hiring a professional to do for you — however most people who have installed smart thermostats will agree that the savings in energy bill costs will easily justify the price of having even a professional installer do the work for you. In fact, the energy savings are so obviously clear that some mainstream utility companies such as Enbridge Gas are now offering monetary incentives for users who install an ecobee3.
The bottom line is that if you’re a HomeKit user in the market for a smart thermostat, the ecobee3 is hands-down the one to buy — especially if you pay your own utility bills, as the cost savings will easily justify the price tag. While there’s still a place for more basic and less expensive HomeKit-enabled thermostats — users who live in apartments or don’t pay their own energy bills won’t likely benefit as much in cost savings from the ecobee3, for instance — optimally managing comfort levels and energy usage isn’t a simple task, and beyond the user-facing features, it’s here where the real power of the ecobee3 lies.
Our Rating
Company and Price
Company: ecobee
Model: ecobee3
Price: $249
Compatible: All HomeKit-capable iPhone, iPad, iPod touch models