Ecobee 3 Vs Ecobee 4: The Ultimate Test

For an amount of time, Ecobee has stood at the forefront of smart thermostat manufacturers in the market. The question is, which thermostat is better ecobee 3 vs ecobee 4?

Ecobee 3 thermostat

Challenger #1


It’s the older model of the two thermostats, but does that mean it’s outdated.

Ecobee 3 thermostat


Challenger #2


It was introduced to knock the ecobee3 of its pedal stool but is it any better than the original. 


Dimensions (Inches)4.05″ x 4.05″ x 1″7.56″ x 7.44″ x 3.46″
Voice AssistantsSiri, Alexa,
Google Assistant
Siri, Alexa,
Google Assistant
Room SensorsUpto 32Upto 32
Far-field Voice RecognitionNoYes
Power Extender KitYesYes
Motion SensorsYesYes
BuyFind Best PriceFind Best Price

#1 – Ecobee 3

Challenger #1 

Ecobee 3 thermostat

The ecobee 3 was designed to help you save money by reducing wasted energy in your household. 

The manufacture claims the ecobee system could save you up to 23% on your bills. 

This is down to the Eco+ mode, which supercharges your energy savings by intelligently heating or cooling your home to your needs.

Ecobee 3 can pair with up to 32 smart sensors, which can help you provide optimal comfort for each room of your home with no problems. 

This allows you to use advanced controls to ensure the temperature is always at a comfortable level. 

Other features include linking the system with your local weather reports or take advantage of vacation mode and more.

The thermostat is straightforward to install and comes with loads of handy walkthrough videos and step by step guides; the whole thing should take about 30-minutes. 

It’s also compatible with the following voice assistants: Apple HomeKit, Google Assistant, and Amazon Alexa.

Key Features

  • Saves up to 23%
  • Installs in 30 minutes
  • Works with all major voice assistants
  • Works with 32 sensors
  • Eco+
  • Includes power extender kit

What Other People Say

They really seemed to love the ecobee thermostat; they brought it to replace their Nest unit, and so far, it has worked very well. The whole system integrated well with their SmartThings and Google Home assistant, so they didn’t have any trouble with the switch.

Another customer loved how many options you had for controlling the smart thermostat. More importantly, it was effortless to use; they felt it was the best for a nontechie person. Their two favorite features were the notifications it provided about the system and the ability to combine with IFTTT.

Final Verdict

Because the ecobee 3 thermostats can link up with up to 32 sensors, it really helps you to control the hot and cold spots throughout your house. The sensors let you easily track and compensate for any temperature fluctuations your home faces.

It might not be considered one of the most powerful thermostats on the market, but it really does perform very well. It’s most significant selling factor is its compatibility with multiple sensors and voice assistants. Overall, a great thermostat which is really easy to install.

What We Liked

  • Works with external sensors
  • Easy to install
  • Nice interface
  • Nice looking
  • Doesn't require a C-wire

What We Didn’t Like

  • Geofencing only work with one phone
  • Occupancy sensors are easily fooled

#2 – Ecobee 4

Again the ecobee 4 thermostats can save its users 23% on their energy bill, so within 2-years of purchase, it can pay for itself, not bad, eh? 

Like the ecobee 3 thermostat, their new and upgraded thermostat can work with multiple room sensors to ensure there are no hot or cold spots.

Using the sensors doesn’t just help you regulate the temperature, it also add with Follow Me/Home and Away mode.

If you’re looking to balance your home’s temperature, there aren’t many thermostats that can compare. 

The thermostat is intelligent enough to switch to the right mode when needed. 

Everything can be controlled using the mobile app, Alexa, or the main interface.

There isn’t much difference when it comes to installing the device is still just as easy. 

The setup is made slightly more accessible because of the built-in Alexa, which lets you voice control, play music, adjust the temperature, and much more.

Key Features

  • Built-in Alexa voice control
  • Includes power extender kit
  • Easy to install
  • Saves 23% on energy
  • Highly compatible
  • Eco+

What Other People Say

They loved it, it was their first smart thermostat, and so far, everything was working correctly. They didn’t have a C-wire, so the installation tips didn’t quite match up. After ringing the support, they managed to get the system up and running.

Another customer had an ecobee4 in their previous home, and after moving out, they released how much they missed the smart thermostat. The thermostat is very convenient to use, which was mainly down to the Amazon Alexa integration.

Final Verdict

The ecobee 4 is one of their newest thermostats on the market. The design doesn’t look too much different from the ecobee3, making it hard for people to see the differences. And if I’m honest, there isn’t much difference with their new model.

The most significant difference is the addition of a built-in Alexa device and the far-field voice recognition. Other than that, they are pretty much the same device. Overall I’m not sure if it deserves the extra price hike unless you haven’t got an Amazon Echo.

What We Liked

  • Built-in Alexa
  • Excellent Features
  • Easy installation
  • Comes with one sensor

What We Didn’t Like

  • Poor audio quality
  • No sunblock feature

Things They Have In Common

There are quite a few similarities with these thermostats that I think we should cover, so let’s get started:

Both thermostats use the same app to control and set up the devices.

So if you’re upgrading from the ecobee3 to the ecobee 4, you shouldn’t have any problems getting switching your settings.

Ecobee interface

They also both work with room sensors, which can help you fix hot and cold spots throughout the house. They can both use up to 32 sensors, so even the larger homes shouldn’t have any problems.

One of the best things about these thermostats is their compatibility. They work with most HVAC systems, including:

  • Gas
  • Electric
  • Oil

And the compatibility doesn’t stop there:

Ecobee thermostats are also compatible with the majority of voice assistants and other third-party apps like:

  • Alexa
  • Google Assistant
  • Apple HomeKit

Having the option of using these third-party products doesn’t just make the thermostats easier to use. It also helps embed the thermostats into your home automation without worrying about compatibility.

Both thermostats include a power extender kit, so you don’t have to worry if your system doesn’t have a C-wire.

The final similarities come with the design, and how the thermostats install, and how much energy they save; it’s nearly identical, so you shouldn’t have too much to worry about if you’re upgrading.

Head To Head: ecobee4 VS ecobee3

As I’ve already mentioned, finding the difference between these two devices can be pretty tricky, which is why I’ve split this section down into rounds. It makes it easier to break down the thermostats and discover which one is better:


There really isn’t much difference when it comes to the design. Both devices look near enough identical; the design has a minimalistic feel while remaining modern and very attractive.

They feature rounded and smooth edges with a very polished finish; they really do look beautiful. One of the most noticeable differences between the thermostats is the speaker that comes with the ecobee 4.

This update was added with the addition of the built-in Amazon Alexa. This means you don’t need to purchase any extra devices to add a voice assistant to your thermostat.

There’s one more difference with the design that I think I should mention, and that’s with the dimensions. The ecobee 4 is slightly larger, but this is probably down to having Alexa built-in to the thermostat.

Choosing a winner for this round was pretty tricky, but in the end, I’m going to go for the ecobee 4, but only because it comes with a speaker and built-in Alexa.

Winner: ecobee4


It’s hard to find faults with the performance of ecobees thermostat; they both perform excellently and could save you up to 23% off your energy bills. These results the smart thermostat paying for itself within the first two years; not too bad, eh?

One of my favorite things about the eco bee performances is how controllable the thermostat is. You can use them with multiple voice assistants, a mobile app, or the main interface.

And it’s not just about how much control you get; it’s the speed at which the thermostat responds that is so impressive. The changes are made almost instantly every time.

This was proven with features like Follow Me, which works by making temperature adjustments based on where movements get sensed.

It’s features like this and Home and Away mode that helps these thermostats save so much money, which is a true testament to their overall performance.

In all honesty, I can’t find any difference between the performance of the two thermostats; they both save you money and perform actions quickly. For this reason, I have to call this round a tie.

Winner: Tie

Room Sensors

Room sensors are an integral part of your smart thermostat system, and they work exactly the same for both the ecobee3 and ecobee4.

You can connect up to 32 sensors to the smart thermostats, which is more than enough, even for the biggest houses. Each sensor can cover around 40 feet through walls and ceilings, so you have to keep that in mind when setting up the system.

The ecobee4 comes with one sensor include; I suggest you place it in the room that gets used the most. If you want to add more, you can, but it does add an extra cost.

Placing the sensors in hot and cold spots around your home helps the thermostat make adjustments to your heating or cooling to get the most out of the HVAC system.

And that’s not the only benefit with room sensors…

They also detect motions so you can use control modes like:

  • Follow Me
  • Home and Away

It helps the thermostat understand which rooms need adjustments based on the movements they detect. Adding room sensors to your system can significantly improve the smart thermostats’ energy efficiency.

Again, the two smart thermostats don’t perform any differently, so we’ll have to call this round a tie too.

Winner: Tie

Amazon Alexa And Other Voice Assistants

The ecobee4 and ecobee 3 work with a range of voice assistants to gain voice control, which is excellent news for any smart homeowner. The significant difference between the two is the ecobee4 has Alexa and far-field voice recognition built-in to the thermostat.

Great news if you haven’t already got an Amazon Echo.

The problem is it does come with a few limitations, so you don’t get the full Alexa feeling, but it’s still pretty neat.

Other than that, both thermostats are the same, and can work with the following assistants:

  • Alexa
  • Siri
  • Google Assistant

For this round, you have to it to ecobee4; the built-in voice assistant pushes it over the line.

Winner: ecobee4


Until recently, it was pretty complicated to set up the thermostats with geofencing; you had to jump through some hoops with either IFTTT or Apple HomeKit to get there.

Now you can set up the geofencing abilities using the mobile app, which makes things 10x easier. Here’s how you set it up:

  • Tap the account icon at the bottom of the apps home screen
  • Hit the Geofence tab and switch it on
  • You'll then be given chooses about the radius of the geofence, which device it works with, and what actions it should take when leaving or arriving
  • Once you've finished setting your preferences, make sure you save them, you can do this by tapping Save at the top right hand of the screen

Once you’ve finished these steps, everything will be ready to go; whenever you leave or enter the geofence radius, the thermostat will perform your desired action.

Winner: Tie

Far-Field Voice Recognition

This is another feature the ecobee 3 lacks, but it’s no surprise without having Alexa built-in in makes very little sense for it to be included.

With the ecobee4, it’s different:

They included far-field voice recognition so the thermostat can hear your instructions no matter where you are in the house.

This feature does work a lot better in small homes for obvious reasons.

Winner: ecobee4

Final Verdict: ecobee 3 vs ecobee 4

If I’m perfectly honest, it’s quite hard to pick a winner from the ecobee3 vs ecobee4 showdown; they’re just too similar. Which is why I think it really comes down to you.

Here’s the thing:

If you haven’t got a voice assistant in your house, you might want to opt for the ecobee4; it comes with Alexa built-in.


If you’re not fussed about Alexa or you already have a voice assistant installed in your home, then you might opt for the ecobee 3.

It has all the other features of ecobee 4 but comes with a much lower cost, which can make it more appealing for people.

As I said, the choice is down to you. Whichever one you pick, I’m sure you’ll be happy with it.

If you’re looking for more thermostat options to control your HVAC system, check out my review of the Honeywell T5 vs T5+.

Frequently Asked Questions

The main difference between the two smart thermostats is the ecobee4 comes with Amazon Alexa built-in. This also means the ecobee 4 is slightly bigger than their previous version. Other than that, there aren’t any other differences.
Yes, the ecobee was recently discontinued, although you can still purchase refurbished ecobee 3 thermostats from their website.

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