Our Nest Gen 2 vs Gen 3 Comparison – What are the Differences Between Them?

It is one of life’s sad maxims that products can’t be allowed to stand still, no matter how perfect you think the old one was. So, there’s always a new Rolls Royce, a new iPhone, a ‘new’ Beatles or Nirvana record on the shelves, and so it goes.

Nest, the crowd funded thermostat control, since acquired by Google, is starting to look that way too. The second generation Nest tidied up the few foibles of the first model, and expanded its compatibility with a wider range of home heating and cooling systems.

But, here comes the inevitable third model with a few more refinements to make it seem more attractive to the smart home crowd.

Cyber Deals Pricing Update: The Nest 3rd Generation has been for a RECORD 43% off at this listing here, but supplies are limited. Be sure to check it out as it may not be live at the time of your visit.

Our comparison takes into account key features, pros and cons, and how they work as far as the user is concerned. Before jumping in, here’s my take on the high level advantages of both:

Nest Gen 2 Advantages Nest Gen 3 Advantages
About $50 cheaper than Gen 3 (see here) Better WiFi connection (802.11b/g/n @ 2.4GHz, and 5GHz a/b/g/n)
Very similar to the Gen 3 Better screen quality and size (easier to read)
New Features:

  • New FarSight Feature (better motion sensing)
  • Now includes hot water/boiler controls

Key Features of the Nest Gen 2 vs Nest 3

Nest 2

  • Pricing: In response to the arrival of the Nest 3, the second generation model has already had a price cut, making it the more attractive for the budget smart home user, or someone looking to upgrade an old first-gen unit.
  • Size: Remember the second generation model was itself a slight reduction on the first. If being skinny is really an essential consideration for a smart thermostat?

The Nest second generation device was 20% slimmer than its predecessor, but is outdone a tiny bit more by the newcomer.

  • Supports Hybrid Heating Systems: The key selling point of the second generation mode was the improved support for a wider range of home heating and HVAC systems, due to its extra pair of connectors. The second generation Nest added support for hybrid heating systems and humidistats.
  • Supports Stage 1-2 Cooling and 1-3 Heating: It also supports all stages of 1-2 stage cooling and 1-3 stage heating systems, which make it more practical for homes with advanced HVAC set ups.

Nest 2 also used the System Match feature to identify and work more in tune with your specific HVAC system.

  • Early On for Cold Mornings: Further features included an Early On mode for cold morning starts, which is particularly useful in cooler climates where it takes some time to warm up the house.
  • Filter Change Reminders: Most people ignore reminders for when filters need changing or cleaning, plus a “true radiant” that improves the use of the thermostat to measure the actual amount of heat created.

Nest 3

  • More Readable Screen: Google’s third-generation smart thermostat product is the first one to try and shake up the device’s screen technology, packing in a new 480×480 screen that improves the readability and distance that information can be seen from.
  • Readable Across the Room: That means it can be read from anywhere in the room, and will better sense when you are in the area, to provide the current time, via a new clock face, and temperature information.

The higher resolution of 229 pixels per inch makes for a better read, but there’s no obvious new features crammed into the display space, or extra information to show.

  • Skinnier (Takes up Less Space): Overall the new device is a little skinnier at 1.21-inches deep, and a smidge wider at 3.3-inches for the extra display.
  • System Reports: Otherwise, Google has resisted over-engineering the Nest with the functional changes including the ability to report issues and faults with your furnace, with the Nest looking for shut off problems on a regular basis. However, that feature will soon filter back into the earlier Nest models, so is not an essential reason to upgrade or rush out and buy the latest model.


Both Nests have a similar front screen and dial on the thermostat and connect to your smartphone or tablet with an iOS or Android app for remote control and management functions.

They both connect to a Heat Link device that connects to the boiler over wireless or existing wiring.

While the screen on the new third generation Nest is a little bigger, and it uses the Farsight sensor to see people and entering the room, there is little functional difference.

With the Nest 2 getting a price cut, you may as well aim for that model. Unless you really need the latest version.

Pros and Cons: Nest Gen 2 vs Gen 3

Nest 2

The Nest 2 is slightly easier to install than its predecessor, which made home installation more of an option. But the main thrust of the Nest 2 was wider support of advanced HVAC and similar systems. Nest 1 claimed compatibility with around 75% of systems, Nest 2 brings that up to 95%.

For designer home lovers the ring design will also help blend into the decor of your room and, overall, the styling is impressive and hard not to love.

Nest 3

The addition of  app controls for your boiler (hot water control) is actually a nice additional feature that might not be readily apparent at first glace. After an initial setup, you’ll be able to control water heating “schedules” to better optimize water usage.

Included in this is the ability to boost or “peak” hot water production via the app which might be ideal if you are having house guests spending the night, etc…

NOTE: In European markets a separate “Heat Link” box will need to be installed to utilize the above feature (standard with Nest 3rd Gen purchase).

Nest 3’s use of its Farsight mechanism to provide information at distance makes the device more welcoming in the smart home, but it is hardly an essential use of the technology.

Moreover, the Nest fails to move with the times, with no reference to external heat readings to better control the heating around various parts of the home.

The only real improvement is its sensing of issues if you have a forced-air furnace system. It can help prevent overheating of these systems and notify users if there could be a problem.

Comparison Table – Features Head-to-Head

Specs Nest 2 Nest 3
Dimensions 3.27-inches diameter

1.26-inches deep

3.3-inches diameter 1.21-inches deep,
Sensors Temperature, Humidity,

Near-Field Activity, Far-Field Activity, Ambient Light

Temperature, Humidity,

Near-Field Activity, Far-Field Activity, FarSight Detector, Ambient Light, Heat Link (Europe)

WiFi Wi-Fi – 802.11b/g/n @2.4GHz plus Zigbee @2.4GHz Wi-Fi – 802.11b/g/n @2.4GHz,   5GHz a/b/g/n, plus Zigbee @2.4GHz,
Price About $199, but see here About $249, but see here

Final Take on the Nest 2 vs 3 – Which one should you go with?

Our Nest Gen 2 vs Gen 3 Comparison – What are the Differences Between Them?

Nest’s engineers are clearly struggling to innovate its core product, with most of the changes cosmetic, and the one real new trick is one that will soon appear in the older models.

So, if you really need to see the temperature from across the room, the third-generation Nest is a helpful update, otherwise you may as well stick with the second-generation model.

In short, if this is your first Nest, the Gen 2 is a competent entry.

Bottom Line: If you already OWN the Nest 2, it’s really not worth the upgrade, unless you really need one of the new features.

Pricing Update: With the Nest 3.0 available for less than $250 here, it’s a no brainer to go with it. At least while this Holiday discount holds…

So Should You Consider Another Thermostat?

You may have heard of some other brands like Ecobee, Honeywell, etc… Below I’ve gathered related topics to help you fully evaluate the market:

  • Nest Thermostat E vs Ecobee4: The new “E” is a cheaper Gen 3 Nest, but here we compare versus the latest Ecobee (which is typically competitive or lower than the Nest).
  • Lyric vs Nest: What I love about Honeywell’s Lyric is that it has “geo fencing” capability which can detect when you – or authorized family members – are close to the house in order to kick start systems.
  • Tado vs Nest: I actually don’t recommend the Tado over the Nest, but this is an interesting comparison to a newcomer (and a good example of how the Nest ecosystem is “winning” overall).
  • Smart Thermostat Buying Guide: Of course, to get my full take on the whole market, this page goes over all the top smart automated thermostat options this year.