The ecobee3 and the ecobee3 lite are admittedly both great products that come with all the benefits of smart thermostats.
Initially the difference between the two models functionality was bigger, because the lite version did not support room sensors. Since April 2017 ecobee3 lite supports room sensors.
Similarities
Remote sensors. Ever since ecobee did some major hardware updates to the lite edition, both of these two smart thermostats are capable of working with remote room sensors. Single room sensor is included in the package when you buy ecobee3 thermostat. However, room sensors for ecobee3 lite in a standard package are sold separately or you can get it by buying together with ecobee3 lite thermostat. They can be used for ecobee3, ecobee3 lite and ecobee4 devices interchangeably.
ecobee3 Smart WiFi Thermostat
Remote sensors gives thermostat possibility to monitor climate and occupancy in the areas where room sensors are placed. Before remote sensors capability was introduced for ecobee3 lite the entire house temperature was decided on the climate data at the thermostat. In the video below you can see how ecobee3 uses room sensors to get the average temperature reading in the rooms and adjust the heating and cooling accordingly.
LCD touchscreen. The ecobee3 and ecobee3 lite share identical 3.5-inch LCD touchscreens and the black exterior case. While their dimensions are ever so slightly different, you’d probably need to hold them up against each other to see that the lite edition is a bit smaller.
Energy usage reports. The ecobee with all of its thermostats, including ecobee3 and ecobee3 lite, provides quite extensive reports on your heating and cooling consumption. Monthly energy reports show how much power you’ve saved over the last 30 days on both of the two thermostats, and they both come with a vacation mode.
If you need to constantly see your power usage at a glance to make sure that you’re not going over a specific goal, then these features are probably important. The fact that both thermostats offer them even with their stock configurations is a plus.
ecobee3 lite Smart Wi-Fi Thermostat
Smart home integration. Apple HomeKit, SmartThings, IFTTT and Amazon Alexa units can interface seamlessly with either of these two units too. That means you won’t have to leave whatever smart home integrated ecosystem you’re living in if you were to buy either version of the thermostat. They even decided to put Power Extender Kits (or PEK) in both packages, which is important if you lack a C-Wire cable.
Key Differences
Internal motion sensor. The ecobee3 lite lacks an internal motion sensor while ecobee3 recognizes occupancy in the area around the thermostat (or remote room sensors if you have them installed). The ecobee3 thermostat will also turn the screen on when someone walks past it. This is useful for some people who need to see what their thermostat is doing without touching it. It might be important to you if you have an ecobee3 installed in your restaurant or body shop and find that your hands are often too greasy to touch the thermostat.
Remote sensors included. The standard ecobee3 lite kit doesn’t come with remote sensors while ecobee3 does have. You can get those separately for either of the ecobee thermostats or get a special package with ecobee3 lite and 2 remote sensors.
Compatibility. It also isn’t compatible with humidifiers and dehumidifiers, which makes it less useful for those who might keep a winter home in a warmer state. If you need your thermostat to interface with equipment that’s keeping an eye on your house when you’re not there, then the ecobee3 lite might come up short in this area.
Comparing the Key Features
Smart occupancy detection is probably the most significant apparent key feature that the ecobee3 lite doesn’t have. The ecobee3 can detect when there are people in the home and figures out when the HVAC systems can get throttled back for substantial energy savings.
On top of this, the added accessory support of the classic ecobee3 edition might be necessary for consumers who have more than just a furnace and an air conditioner installed in their home. Barring this, though, you shouldn’t count either option out just yet.
Mobile Application
Currently, ecobee only offers one mobile app for users of all of their devices. The app is offered for both iOS and Android devices. It will automatically recognize which version you have and adjust itself accordingly. Naturally, the app would lock you out of using any feature that the ecobee3 lite thermostat doesn’t have.
Notably, you can still use a customized Web portal with both versions of the thermostat. Even lite edition users will be able to look at the weather forecast for their area, adjust the temperature and schedule or set preferences from inside the account.
You’ll be able to manage the thermostat regardless of what sort of device you’re logged in from. Even if you use Linux or FreeBSD instead of a commercial operating system, then this makes either version a wise choice as you won’t need a mobile app to control your thermostat.
Installation
The ecobee3 lite is debatably slightly easier to install since it comes with fewer parts. Both the ecobee lite and classic editions of ecobee3 come with the necessary screws and drywall plugs to install the thermostat directly over the previous one that you once used.
The one major difference is that the ecobee lite is ever so slightly smaller, which may be important if you’re mounting it somewhere that can’t support much weight at all.
Both units expect a 24VAC 2A line, which means that neither of them is compatible with high voltage and mini volt HVAC systems. While this shouldn’t influence most residential users, this is a bit of a strike against both the ecobee3 and ecobee3 lite thermostats. Nevertheless, these systems are increasingly rare so this kind of compatibility might not be that important to you anyway.
Smart Features & Home Automation
The fact that the ecobee3 comes with so much support for these units as well as options like smart occupancy detection means that you might look at it as the clear winner in the smart features fight. That being said, you’ll need to think about whether or not these options are important to you before you make a final decision.
Once you’ve installed them, the configuration process for the ecobee3 lite and the ecobee3 are more or less the same. You can access the thermostat menu by touching the so-called pancake icon to get a much larger array of features. While you’ll usually see it referred to as the pancake or even hamburger icon, ecobee intended this to represent a set of horizontal lines suggestive of a list.
This list of options should include system and comfort settings as well as a scheduler on both versions of the device. You should also see vacation options, alerts, and technical information.
The ecobee3 lite doesn’t have all the functionality of the original ecobee3 thermostat, but many users will not notice that. Those who need additional integration functions will be disappointed with the ecobee3 lite, while other users might prefer the lite version simply because fewer features translates into less configuration.
Energy Savings Potential
Ecobee company claims that you can save an average of 23 percent annually in heating and cooling costs. These figures were based on the desired temperature of 72°F, so if you don’t mind it being cooler in the winter or warmer than this in the summer you stand to save much more with either option.
A good idea would be to set the thermostat around 67 or 68°F in the winter and perhaps around 81 or 82°F in the summer depending on what you can handle. The method used to set the thermostat is identical on both models, so this kind of a switch away from the defaults would be easy to make regardless of which version you choose.
conclusion
If things keep going the way that they are, then eventually there won’t be much of an appreciable difference between any of the various versions of the ecobee3 thermostat.
As it stands today, the ecobee3 lite is less expensive than its full-featured older brother.
However, ecobee3 package already contains one room sensor, where with ecobee3 lite you need to purchase them separately.
There isn’t a clear winner because both versions do exactly what they set out to do. If you’re looking to save some money and you don’t have any need for the additional features that come with the full ecobee3 Wi-Fi thermostat such as room sensors and occupancy monitoring, then you can probably better off with the ecobee3 lite.
However, if you considering to manage climate in large residency with room sensors you probably a better off with the full ecobee3 version. You will get one room sensor already with the package and can purchase additional ones later.
Keep your eye on changes that the company has been making and also the prices of each thermostats, because they change from time to time.