Nest Gen 2 vs Gen 3 – What are the differences? Which one to get?

When was the last time you actually thought about your home thermostat? If we are being serious, unless it has given you problems, it just sits on the wall clicking and turning things on and off.

However, thermostats have taken advantage of recent technological advances and are now incorporated into the true smart home lifestyle. In 2011, Google introduced the Nest learning thermostat. Since then it has gone through two iterations and changes, and for the better.

If you want to compare the latest two models, the Nest 2 and the Nest 3, you are in luck. I am going to dive deep into these thermostats and find out exactly what is going on behind those huge LCD screens. I will compare the two models and give you an overview of the features. I will even answer the most common questions and show you side-by-side which thermostat is the best.

Continue on to the entire article below for the full rundown and my pick for the best of the Nest. (Did you see what I did there?) However, if you have come to love and respect my articles, my pick is the Nest 3rd Generation thermostat.


👉 If it’s your first time buying a smart thermostat, go with Nest 3 as the extra features will be worth the difference in the price tag to you.

👉 If you already have a Nest 2, then you don’t need to upgrade to Nest 3 as the extra features will not do much for you.

The Differences

What does one have that the other doesn’t? When deciding which is right for you, it can make all the difference.

  • Nest 3 has a higher resolution screen than the Nest 2.
  • The Nest gen 2 does not support Bluetooth or WiFi 5Ghz; Nest gen 3 supports both.
  • Nest 3rd generation has safety alerts and Farsight; Nest 2nd generation does not.
  • Nest 3 has five more sensors than the Nest 2.
  • “Furnace Heads Up” (see below for details) is installed for Nest gen 3 by default, not in Nest gen 2.
  • Nest 3 is compatible with the Remote Sensor accessory, Nest 2 is not

The Similarities

When you know what they can both do, it may prevent you from spending too much for things you don’t need.

  • They both support both iOS and Android as well as WiFi 801.1 b/g/n at the 2.4Ghz frequency.
  • Both the Nest 2 and the Nest 3 are compatible with Amazon Alexa, as well as most other smart home integration products, except for Apple HomeKit.
  • Each has the exact same installation procedure and comes with all the tools you will need.
  • A 2-year limited warranty is offered for both the Nest gen 2 and the Nest gen 3.
  • Auto-away is a feature for both thermostats.
  • You can use a remote control on both as well.
  • Airwave, Nest leaf, and energy reports are standard for both versions.

Side By Side Comparison Chart

Nest 2 Nest 3
Size 3.2” diameter 1.26” from wall 3.3” diameter 1.21” from wall
Screen Resolution 24 colors 320×320 24 colors 480×480
Farsight No Yes
Airwave and Nest Leaf Yes Yes
WiFi Support 801.1 b/g/n 2.4G 801.1 b/g/n 2.4/5G
Amazon Alexa Yes Yes
Smart Home Integration Yes Yes
Furnace Heads Up No Yes
Heat Link & Cool to Dry Yes Yes
Remote Control Mobile App Mobile App
Auto-Adjust No Yes
Sunblock No Yes
Time-to-Temp No Yes
Safety Alerts No Yes
Price Check on Amazon Check on Amazon


Details of Features

Some of these features may not make a lot of sense to you. Understandably, no one outside of Nest knew what Airwave was at first. I will dig into the deep details of the features, so you know what is really going on.

1. Amazon Alexa and Smart Home Integration

Allow me to say this right off the get-go: Nest is a product of Google. As such there is not, nor will there probably ever be Apple HomeKit integration. We will most likely have Coke and Pepsi being served in the same restaurant first.

That being said, virtually every other 3rd party smart home integration product is compatible with Nest generation 2 and Nest generation 3 thermostats. This includes Amazon Alexa, Google Home, IFTTT, SmartThings, Wink, Philips Hue, SkyBell HD; I could go on. You get the idea.

With these apps and products, you can control your thermostat with your voice, with your phone, and probably in the near future even with Google Glasses and your mind.

I couldn’t possibly test each of these apps out for reliability. However, reports and reviews have not yet yielded any issues with any of them aside from the rare setup problem. These problems, if I am being honest, were mostly due to user error and not the thermostat or the app.

Bottom Line: This is a tie. They will both connect to almost anything, except Apple HomeKit, of course.

2. Airwave and Nest Leaf

Airwave is actually one of the coolest features of Nest learning thermostats. As our air conditioners run, cold air is caught in the vents, around the evaporator and refrigerant lines. What Airwave does is sense when this cold air is in the system and turns the air conditioner off.

The fans will continue to blow and force this trapped colder air out into your home. You will still have the effects of the air conditioner, but you won’t have the energy costs. It is arguably the most cost-effective solution of any thermostat.

The Nest Leaf is a visual aid to help you save money on your energy bills. When you first install the thermostat, you will notice a little green leaf icon on the display. Over the next couple of days, this leaf will disappear (when your thermostat learns your home and temperature preferences.) and will only come on when you set your thermostat to energy saving temperatures.

Each time the thermostat will attempt to get you to lower your heat or raise your air conditioner by a degree or two. When you do, each degree will save you about five percent annually. When you are in this preferred savings range, the leaf icon will come on showing you how wonderful of a job you are doing saving money.

Bottom Line: Another tie. All Nest gen 2 and Nest gen 3 thermostats have Airwave and feature the Nest Leaf.

3. Heat Link and Cool to Dry

I want to talk about these two features because there is a lot of confusion about them. I will start with the Cool to Dry because that affects everyone.

Cool to Dry is a humidity sensor feature that alerts the thermostat when there is high humidity inside the home. The thermostat will then turn the air conditioner on for a short while to lower the humidity in the house.

Now the most confusing part is the Heat Link. Many customers are confused about this little gem. Rightfully so. If you are in the United States, you don’t have it. Not at all.

If, however, you live inside the EU, Heat Link is a must-have item included with the installation of the thermostat. In the Nest generation 2, the heat link was a high voltage regulator that monitors the heater. It would relay the information to the thermostat to let it know when to turn on or off.

In the Nest generation 3, the Heat link came with 3 extra wires and allowed the unit to control the hot water as well as the hot air. This is United Kingdom only piece because of their high voltage (240 V) that would otherwise destroy the low voltage (12 V) thermostat.

Bottom Line: Nest gen 3 wins. Especially if you are in the UK, the Heat Link is a great addition to energy control.

4. Farsight and Sunblock

Two more features that the Nest 3 has that the Nest 2 does not are Farsight and Sunblock. Technically that statement isn’t completely true. You see, there is a sensor on the thermostat that will tell the screen to come on when you are near it.

This same sensor also alerts the thermostat is anyone is home (or not) by using a wide angle to look for movement. Nest 2 has this, but you must be within 3 feet of the thermostat to activate the screen. With Farsight, that distance has increased to about ten feet, hence the name.

Sunblock, on the other hand, is only available on the Nest 3rd generation thermostats. This is a new sensor that can detect if the thermostat is heating up due to direct sunlight. If so, it will control the thermostat so that your home is not wrongly cooled.

Bottom Line: Nest 3 wins. Sunblock is a nice touch in energy savings, and Farsight is a vast improvement over Nest 2.

5. Furnace Heads Up

New to the Nest 3rd generation thermostats, Furnace Heads Up is a feature of the Mobile app that will let you know if anything crazy is happening with your heating unit.

You will get alerts that let you know if the system detects anything unusual, such as frequent shutdowns, or running too long after power off. You will receive an alert through the app so that you can take steps to prevent major problems down the line.

Even something as simple as forgetting to change your air filter can cause your energy savings to vanish. Nest 3 takes steps to keep your energy savings low and can now tell you more precisely how to do so.

Bottom Line: Another win for Nest 3rd gen. Furnace Heads Up can be a money saving addition to the mobile app.

Frequently Asked Questions

The most common questions about the Nest 2 and Nest 3 thermostats, answered for you, right here, right now.

Q: Can you adjust the temperature and settings with the touchscreen?

Absolutely not. Only because it is not a touchscreen. However, what you can do is tap the screen to turn it on and use the dial to make your changes.

You can also make your account on the Nest website and download the free mobile app to control your thermostat remotely.

Q: Will the reports tell me how long the air conditioner was running?

This is an absolute yes. You can log in to your reports, and you will be able to view the history of your system.

In this history, you will be able to see the previous cycles and how long they ran for. It is great information, and you will be able to make adjustments to your cycles based on the information, which leads to more Nest Leafs and greater energy savings.

Q: I rent my house on a travel website, can I lock the thermostat so that renters can’t alter the settings?

Once you create your account on the Nest website and download the app, you can set a thermostat lock that will require a four-digit PIN to get into.

However, this will only prevent changes to the temperature range you have set in the scheduling. It is still effective unless of course, you let others know what your PIN is.

Q: What does the Nest 3rd generation thermostat do that the Nest 2nd generation thermostat can’t?

Seriously? Did you just scroll through the entire article without reading a word? I swear I spent a few sentences on this at least.

Quick recap: Nest 3 has more sensors, controls more HVAC items, is smarter, more energy efficient, has a bigger display with Farsight enabled so you can activate if from further away.

If you want details, read the article. It’s all there. I promise.

Q: When I am not home, but the kids are, will the thermostat know, or is only in my cell range?

The thermostat will know. It will also attempt to feed your poor, neglected children. It will fail, but at least it tried.

The Nest 2 and Nest 3 have sensors on the face that can detect movement to know if someone is in the home. It will run the schedule accordingly. It will also use the Home-Away feature with your cell phone. However, if you are gone, and your children are left there alone, it will know they are there and keep the temperature of the home comfortable for them.

Q: I have a home with an older style mercury thermostat. Will the Nest gen 2 or Nest gen 3 work with my current wiring?

Just give it a try! What’s the worst that could happen? I mean really, it’s just an air conditioner and heater, right?

On a serious note, the Nest support is actually quite good. Before you make a purchase, you just need to remove the cover of your existing thermostat to show the wires (and clean it off, it is bound to be dirty in there). Take a picture of the thermostat with the wires exposed and send it the Nest Support.

They will look at your photo (laugh at you a little) and then report back if their thermostats are compatible with your existing wires. Not only that, but they will also tell you which wires will be connected to your new Nest thermostat and where they go.

Q: I have two separate AC units.

I have a goldfish. I mean, while we are talking about things that don’t matter. I assume you want to know if you need one or two thermostats, or if they will work in tandem?

To answer my questions: You will need two thermostats. Each one will take the temperature of the area (or floor) it is on, separately. They will not work together. Each one will have a slightly different learning curve as well as schedule. However, they will still be efficient for your systems, and you will have the benefit of the energy savings they provide.

Q: Why didn’t you talk about the different colored rings?

I knew you would ask and I wanted to give you your moment in the spotlight. The Nest gen 2 has a silver-colored ring, and that is your only option for color.

However, with the Nest gen 3, you have four color options: Silver (I know, you are surprised); Copper (for those that decorate in Steampunk); White (Because boring is the new… it’s boring); and Black (since it needs to match your new microwave – How did I know??).

What We Like About the Nest 2

  • Installation is simple.
  • The energy savings are noticeable in the first few months.
  • Airwave keeps from overusing the air conditioner.
  • Amazon Alexa and other Smart Home devices integration are easy.

What We Like About the Nest 3

  • Sunblock is a cool feature for certain mounting areas.
  • The mobile app updates for Furnace Heads Up helps keep your system running well.
  • Match any décor with color ring variations.
  • Safety alerts and Away monitoring allow you to keep an eye on your home where ever you are.

In Conclusion

Which thermostat is right for you? More importantly, if you already have a Nest 2nd gen, should you upgrade to a Nest 3rd gen?

If you already have a Nest 2, I would recommend you keep it. The advancements in the Nest 3 really aren’t worth the extra cost and the hassle for you. You won’t save any more or less in your energy bill and to be quite honest, the extra sensors and app features are good, even alluring, but you will find that they don’t do much for you.

However, if you don’t already have a smart thermostat, then you really need to go with the Nest 3. Sure, the Nest 2 will do you well enough, but you aren’t saving a whole lot of money by taking the older model. If you are installing a smart thermostat for the first time, the extra features in the Nest 3rd gen will be an actual difference maker over the Nest 2nd gen, for you.

The bottom line is that even with the small differences, either thermostat will work great for your needs. If you are a preexisting owner, there isn’t a need to upgrade. If you are new to the game, get the Nest 3, you will be happy you did.

Check here to see all the smart thermostat deals on Amazon today. 

10 thoughts on “Nest Gen 2 vs Gen 3 – What are the differences? Which one to get?”

  1. I currently have a nest 2 in my front living room. In the same room I just installed a gas fireplace. Mainly for ambiance, but also as backup heating in case the power goes out. The problem is that the thermostat heats up because of the fireplace heat. This is not bad but the far rooms from the thermostat tend to be a lot cooler. The reason I am upgrading from a 2 to 3 is the compatibility with the remote sensors as they are only compatible with the 3rd version. I should able to put a remote sensor in one of the far rooms and make the temperature in that area the priority. Am I off my rocker here or does that sound like a reason to upgrade?

    1. Hi Dan,

      The situation you are describing is the perfect use case for the remote sensors, so I’d say it’s a pretty good reason to upgrade.

      The Nest E is also compatible with the remote sensor, in case that was not on your radar.


  2. Dan & Kevin, I think this is only partly correct

    While through the remote sensors you could make the temperature in the “far away” rooms the priority, the sensors and thermostat cannot control the air flow. As a result you could either make the living room the priority and be comfortable there (and probably a bit a bit to cold in the “far away” rooms. Or you could make the “far away” rooms the priority and be to hot in the living room. If you want to control the air flow you need a sophisticated 2 or 3 zone heating system (residential) and install 2 or 3 thermostats (one for each zone). The thermostats control the valves in the duct work and the air flow to each zone.


    1. Hi Paul,

      Thank you for explaining this in detail. You are 100% correct and I agree that residential heating/cooling systems are not able to selectively heat one room more than another.

      To do that, I try to just open the vent more in one room and close the vent partly in another room to achieve the amount of heating desired in each room. It’s not the ideal solution but works well enough, for me at least.

      Thanks again for your comment!

  3. We are searching for a thermostat to put in my in-laws’ condo. She is legally blind but can read large numbers and letters. He has dementia and keeps the house so hot she can’t stand it, and can’t sleep, and she can’t see their current thermostat well enough to control it. If we installed this, and set parameters per her preferences, and put the app on our phone (not their phone, they don’t use smartphones…..age 93…..), could we control their temperature from 2000 miles away? They would still be able to control it manually, AND we could check on it from afar and override if necessary? Thanks in advance–

    1. Hi Meg,

      Yes, it will work as you described. They would be able to control the thermostat locally and you can check it/change the settings as needed.

  4. For folks reading this who are looking to purchase one of these, and perhaps you are looking at used units on craigslist, facebook marketplace, ebay, or whatever… *here* *is* *the* *bottom* *line*. Don’t spend the extra money on a new one, and especially don’t spend the extra money on a 3rd generation. The 2nd generation is completely fine, has all of the features that you need, will turn your ac / heat on and off and do all the fundamental functions that allegedly better 3rd generation will do, for less money.

    People just get hung up on a narrative that “well If there’s a gen 2 and a gen 3 then three must be the best! I need the best! Nothing less than the best!”, and at the point, Nests marketing department has won… because for what you will be using this for, there is of absolutely no difference, other than paying more money than needed and necessary. Now, as someone who buys these on a regular basis, I can tell you that I specifically only buy 2nd gen because that’s all that is needed, and spending more on a 3rd is just, sorry to say, silly.

    The 3rd gen does both 2g & 5g WiFi. 2g WiFi works longer distances, provides a stronger consistent WiFi signal, is less susceptible to noise / interference, and is more stable / reliable of a frequency spectrum. 5g range is more susceptible to interference and has a shorter range / reliability. 5g WiFi is technically “faster”, but only when in extraordinarily close proximity, and would only be noticeable on high bandwidth things, say something as an Apple TV, gaming console, Netflix streaming, laptop downloading large file, etc aka devices that are streaming large files and require a lot of bandwidth , but again, you would want to be within very close proximity to the router for that. Second to that whole concept, the bandwidth that a nest thermostat uses is almost negligible. It sends and receives insignificantly small “packets” of information to the internet, which even at 2g happen in nanoseconds and is instantaneous. The fact that they incorporate 5g puzzles me, because there is literally no practical or sensible need for that. all routers will always be, always, 2g… some are 2g & 5g, but any gen 2 will always work no matter what. I have had MORE issues with clients who have a gen 3 on 5g, because it drops the connection, because the nest is on one side of the house and the router is on the other, and they put it on the 5g networking, thinking it’s “faster and better!” when really it’s weaker and more unreliable. …so over I go, to re-set the whole thing up, put it and lock it into the 2g network (like a 2nd gen just does by default), and insist to the person not to change anything!

    Also, the 3rd gen has Bluetooth?! I still can not wrap my head around why that is even necessary?? Bluetooth range is mere feet, and any and all connectivity of relevance needs to occur over WiFi, which Bluetooth is not. If anything, if the 1st generation was Bluetooth and only worked from within the house and not remotely outside the house, and the 2nd gen got rid of Bluetooth and offered WiFi, to then allow its connectivity to be infinite, that would make more sense… in that they got rid of something to improve something. However, if you can start to see what I’m getting at here, they “added” something in the 3rd gen that just completely makes nooo sense as to why they would even do that?

    So, in short, if you’d like to spend more money than necessary to have 5g which I would advise not using and Bluetooth which I assure you that you are NEVER ever going to use, then by all means, be my guest and pay more than necessary for the exact same thing with weird unnecessary and irrelevant differences… or, just do it right, get the 2nd gen, save yourself a couple extra bucks in the process.

    Let me put it another way: on one hand I’m stoked that there are gaggles if folks spending way more than they need to on these gen 3’s, because it makes the 2nd gen that much more sustainability affordable.

    Make sense? Hopefully that does, because it took forever to type out two thumbs at a time 😉

    1. It makes sense, and thank you for sharing your experience with us!

      Since prices fluctuate from time to time, picking up whichever model is cheaper when you are looking to buy one is the way to go.

  5. I also loved your sense of humor. The 2nd Gen is an old unit now (August 2020) and CHEAP on eBay (<$75 USD) if you don't need the "base", which is available on Amazon for $12.99.

    I have a small house, about 1200SQF. My office is right in front of the thermostat as I "go to work" in my home office. It sounds like the only convenience I would get by going with a new 3rd Gen ($219 on Amazon right now) is the ability to have remote sensors, Furnace heads up and 5Ghz Wifi. Did I read this wrong?

    Having a small house, no need for Farsight… Maybe a remote sensor 12 feet into my home office for the amount of heat I produce, doesn't give me the need for high res display or bluetooth (I have a DOT in 3 rooms and one is my office) and my 2.4 Ghz extends 5 bars to my entire property of 1 acre, due to enterprise antennas. I'm thinking I should invest the money for a 2nd Gen. A no brainer based on your review.

    What do you think?

    Thisguy rambled on about features without a clear goal… or understanding why Bluetooth is included… I like that he is worried about spending money on frivolous expenditures. I am too.

    THISGUY, bluetooth is a separate, but available, connectivity method from WIFI. You use one when the other doesn't make sense or doesn't work… Different channels and all. It didn't increase the cost to add it! Just insure your Echo is within 30 feet (probably less) to use it.

    Ian – Systems Engineer

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