In this comparison, I will focus on the Top Wifi Thermostats in 2017. I will be comparing 8 of the top wi-fi thermostats and they are:
 Nest 3rd gen
 Sensi ST75
 Honeywell RTH9580WF
 Ecobee3 Lite
 Sensi UP 500W
 Honeywell Lyric T5.
The comparison contains a series of easy to read charts in which the eight wi-fi thermostats against one another.
Each chart contains a small set of features.
All in all over 50 features are compared.
Those sections are:
 Basic Specifications
 Design, Power & Connection
 Screen Features
 Smart Heating Features
 Energy & Weather
 HVAC Compatibility
 HVAC Compatibility (2)
 Remote Access
 Home Automation
 Ratings & Reviews
 Basic Specifications
In terms of manufacturer there is a mixture of traditional thermostat brands such as Honeywell and Emerson together with some newer companies that have only been around for a few years, such as Ecobee.
In terms of when these wifi thermostats were first on sale, the Sensi UP500W is the oldest thermostat in this group. It has been on sale from December 2012.
The newest thermostats are the Ecobee4 and the Sensi ST75, which were launched a few months ago in April 2017.
The next feature compares the weight of each thermostat. The heaviest seems to be the Ecobee3 which weighs 1.4 lbs or just over 22 ounces.
The lightest are the two Honeywell thermostats- the RTH95 and the Lyric T5.
In terms of dimensions, the largest thermostat is the UP500W which is nearly 6 inches long by 3.8 inches wide by 0.9 inches thick.
The smallest thermostat is the Nest (3rd Gen) which is 3.3 inches long and wide by 1.2 inches thick.
And the final feature is the price. Obviously prices are subject to change. The cheapest thermostat is the Lyric T5 which is just over $117 and the most expensive is the Nest at just over $248.
 Design, Connection and Power
Every one of these thermostats is available in only one color. The only exception is the Nest, which is available in four colors- black, white, silver and copper.
Thinking about materials, all of these thermostats are made of plastic apart from the Nest.
All of these thermostats are powered by a 24V C or common wire.
If your system does not have a C wire, there are alternatives available.
The Ecobee thermostats come with Power Extender Kits (PEKs) and the Nest can be powered by a 120V cable whereas the Sensi UP500W can also be powered by two AA batteries.
Focusing on the warranties, the best warranties are available for the two Sensi thermostats- the ST75 and the UP500W, which come with a whooping 5 year warranty.
The Nest and the Honeywell thermostats only come with a two year warranty.
Lastly, in this section let’s look at Wi-Fi connection.
All of these thermostats will connect to a 2.4Ghz Wi-Fi network- which is what the overwhelming majority of us have at home.
They use the WPA and WPA2 security protocols.
The Nest thermostat is unique in this group because it will connect to Wi-Fi networks running at a 5 Ghz speed, which are becoming more common in homes across the US.
 Screen Features
All of the thermostats in this selection have color screens apart from the UP500W and the Lyric T5 which are not color but they are backlit.
In terms of the size of the screen, the Nest has the smallest screen at just over 2 inches in diameter, whereas the RTH95 has the largest at 3.75 inches in diameter.
All of these thermostats have touchscreens apart from the UP500W.
In terms of resolution, the Nest has the top resolution at 480 x 480 pixels, whereas the ST75 has the lowest at 272 x 480 pixels.
Unfortunately, I could not find any details about the resolution of the Lyric T5 or the UP500W.
The final feature I have labelled as “proximity”. This is the ability of the thermostat to detect that you are close by and to “switch on” the display.
The only thermostats that can do this are the Nest and the Ecobee thermostats.
 Smart Heating Features
In this next section, I dig a little deeper into some of the smart heating features of the thermostats.
These features are:
All of the thermostats can be programmed manually, which is when a user enters in a set of times and temperature ranges that the thermostat operates within.
All of these thermostats can be manually programmed via the app. Many of them can be programmed via a web account and some of them can be programmed on the unit themselves.
The Nest is unique because as well as a manual programming function, it also has an automatic setting that remembers the times and the temperatures that you like from remembering the adjustments that you make as you go along. Schedule
Moving onto scheduling, all of these thermostats can have a different schedule for each day of the week.
The Nest and the Ecobee thermostats can have an unlimited number of events within each day, whereas the ST75 and the UP500W only offer 7 events per day.
To clarify, an event is one instruction such as “turn on heating at 6am, turn off heating at 8am. Keep temperature at 65°F”
 Room Sensors
Room sensors are small plastic sensors that detect temperature and motion. They are placed in different rooms around the house and they connect wirelessly to the smart thermostat.
Currently it is only the Ecobee thermostats that use them.
Geofencing is the ability of your smart thermostat to be controlled by the location of your phone.
It is an invisible boundary that you can create somewhere in your neighbourhood and when that boundary is crossed your thermostat is either switched on or off.
All of these thermostats have geofencing capabilities but I am not sure if the RTH95 does.
 Energy and Weather
The Ecobee thermostats promise savings of up to 23% every year and the nest thermostat promise a saving of 10 to 12% on heating and 15% on calling.
The Sensi thermostats promised savings of up to 30%.
The Ecobee and Nest thermostat have energy reports.
These reports will be emailed to you monthly in order that you can see how you have use your energy in the past month.
Also, you can access your energy use at any point by looking at your account on your app or via the web portal. This will allow you to see you usage and savings over a longer time period than just a month.
There are only two thermostats that display the outside temperature. Both of these thermostats are made by Honeywell – the RTH 95 and the lyric T5.
The other thermostats don’t display the outside temperature because they provide more detailed weather forecasts.
The Ecobee thermostats and the Nest thermostat provide seven-day forecasts which can be viewed on the unit or on the app.
The Sensi thermostats provide the current weather via the app.
The RTH 95 and the Lyric T5 provide a seven day for forecast via the app.
 HVAC Compatability
There are a great variety of Heating, Ventilation and Cooling (HVAC) systems available.
All of these thermostats have been designed to work with 24 Volt systems, which are the most common.
There are 4 main types and they are:
 Dual Fuel
Other fairly common systems that are not powered by 24 Volts are
 Electric baseboards
All of the 8 best Wi-Fi thermostats have exactly the same compatibility.
The thermostats are all compatible with the gas, electric, oil and dual fuel systems.
None of the thermostat are compatible with Minivolt or baseboard systems.
 HVAC Compatibility (2)
With conventional and heat pump systems all of these thermostats are compatible with multiple stage heating and Cooling.
 Conventional Systems
In fact, with conventional systems all of the thermostats are compatible with two stages of heating and two stages of cooling. Heat Pump Systems
With the heat pump systems, all of the thermostats are compatible with four stages of heating and two stages of cooling apart from the Honeywell thermostats- Dr T H 95 and the lyric T5.
All of these thermostats work with a humidifier.
 Hot Water
All of these thermostats are compatible with hot water systems apart from the Sensi ST75 and the UP500W.
 Remote Access
In this section, I will provide an overview of the different ways in which the thermostats can be remotely accessed.
Remote access is simply the ability to control a thermostat without physically touching it.
So you can be on the other side of the room from the thermostat or the other side of the world.
Thermostat can either be remotely accessed via apps for smartphones and tablets or by using an Internet browser.
The different features in remote access are
To access any of these thermostats on an iPhone or iPad, the device needs to be running iOS 9 or later. The Sensi ST75 and the UP500w require iOS 10 or later.
To access any of the thermostats on a smartphone or tablet that is running Android, depends on what specific device you are using.
You can find out more by visiting the Google Play store on your device.
 Windows 10
None of these thermostats have a Windows 10 app, probably because so few devices use Windows 10.
The Honeywell thermostats are the only ones in this group that don’t allow you to access the thermostats via any browsers at all.
All the other thermostats allow you to access your account using browsers such as Firefox, Internet Explorer, Google Chrome and Safari.
 Home Automation
Home Automation is the ability of smart devices to work with other smart devices.
In my comparison I have listed 7 different home automation systems and compared how these 8 thermostats work with them.
IFTTT or if this then that is an automation website and app that enables you to connect different smart devices and different web services together.
Only the Sensi thermostats don’t work with this system. All the other thermostats have dedicated services and applets on if this then that.
Amazon Echo is Amazon’s voice assistant. The system is powered by two way speakers such as the Amazon Echo and the Amazon Dot. All of these thermostats work with the Amazon Echo system, which is not surprising as Amazon is a place where so many of these thermostats are sold.
This system enables you to command your thermostat using your voice instead of having to use an app or a web portal.
And so a common command to your thermostat could be “Alexa, turn the temperature up to 65 °F”
In order for it to work you need to have bought either the Amazon echo or the Dot.
However, what makes the Ecobee4 very unique is that you do not need to have an Echo or a Dot because the Ecobee 4, as well as being a smart thermostat, behaves as if it is an Echo or a Dot.
Apple Homekit is Apple’s home automation system. Only three of these thermostats do not work with Apple Homekit. Those are the the Nest, Sensi ST75 and the Sensi UP500W.
Six of these thermostats work with the Wink system. The RTH 95 and the lyric T5 are the thermostat that are incompatible with it.
Smart Things is Samsung’s smart home system. Five of these thermostats work with Smart Things. The 3 thermostats that don’t are the Nest, Sensi ST75 and the Sensi UP500W.
 Ratings and Reviews
My final section is all about the ratings and reviews that these thermostats have received on Amazon.
What I have tried to do is to show some of the most helpful statistics to help us work out which are the most popular and the most reliable thermostats.
To state the obvious, these numbers will change on an almost daily basis but I think that the overall trends that these numbers reveal will not change that much and therefore can really help us.
All but one of these thermostats have a rating of greater than four out of five. the Lyric T5 has the lowest rating 3.8 out of 5.
The nest has the highest rating of 4.6 out of 5.
Number of Reviews
The nest also has the highest number of reviews which is 13719. In terms of the number of reviews, it’s next nearest rival is the Eobee3 which has 3893 reviews written.
The numbers in pink are the number of reviews which are written (on average) every month.
Even using this criteria, the Nest is way out in front.
The Sensi UP500W has the most questions that have been answered of any of these thermostats.
It has had over 1000 questions answered.
The Ecobee3 and the Nest have had over 600 questions answered.
% 5 Star Reviews
Looking at the percentage of reviews that have rated a product as being five stars, the Nest once again comes out on top with 87% of all of its reviews rating it as five stars.
The next most highly rated the thermostats are the Ecobee3 and the Ecobee3 Lite.
The Lyric T5 has the lowest number of 5 star reviews with only 50% of all of its reviews rating it as five star.
% Reviews 1 Star
The percentage of reviews that rate a product as one star can also be useful indicator but with this rating the better devices have very low numbers.
What is incredible here is the ST75 has 0% of its reviews rating it as one star. The nest and the Ecobee thermostats also have very low percentages for this feature.
This comparison displays the latest price for each of these thermostats and as I have said before just remember that these prices are subject to change.