Google's Nest Thermostat is the first thing you should buy for your smart home

Sure, adjusting your heating or A/C with your phone or voice is nifty, but that's not why you get a smart thermostat. You get it to save money.

The original Nest Learning Thermostat (now on its third generation), promised to reduce your heating and cooling bill while learning from — and adapting to — your behavior. But, with a price tag of $250, it required a leap of faith and outlay of cash too dear for many. Now, Google's offering a simpler version of the same concept for just over half the price, but with a few sacrifices.

Simply called the "Nest Thermostat," it's a far less daunting $130... but many utility companies are willing to subsidize it, bringing the cost down to under $60 (you can check if your gas or electricity provider is one of them and if you qualify for any rebate over here). But is it worth the effort?

No Google? No problem

Google acquired Nest back in 2014 and left its branding alone until 2019 when it made Nest part of the nomenclature for its smart speakers and other devices. Naturally, the Nest Thermostat integrates especially well with Google's smart home kit and Android phones... but neither is essential. If you're an Apple user, you can download the Google Home app from the App Store, set it, and largely forget it. And if you've already got Amazon Echo speakers, the Nest Thermostat will work perfectly.

Before ordering the Nest Thermostat, you need to check that your heating, ventilation, and air conditioning (HVAC) system is compatible with it. Head to this webpage to do that. The device supports a range of heating fuel sources (gas, electric, oil, propane, and even geothermal), and heat delivery (forced air, in-floor radiant, and radiators). Unless your system is ancient, or high-voltage, you should be good to go.

Another thing to consider when ordering is that you may need the optional ($14.99) trim kit that hides the holes in the wall your previous thermostat controller may leave behind. The Nest Thermostat is pretty dainty, so if your existing controller is larger (break out the tape measure, the Nest's diameter is 3.3 inches) you'll almost certainly need the trim kit. It's a little cheeky to charge $15 for an oval piece of plastic with a few holes in it and a couple of screws, but hey, that's capitalism for you.

DIY install

Installing the Nest Thermostat took me about half an hour. Google offers step-by-step instructions you can follow on a smartphone, tablet, or laptop. You'll need to turn off the power to your HVAC system, remove the cover of your current thermostat controller, identify which wire is which, disconnect and label each wire using the included stickers, and then remove the mounting plate for the old controller.

Afterward, you need to attach the Nest mounting plate to the wall with a pair of included screws (there are plugs if you need them, and a built-in, tiny spirit level to make sure you get it straight). Then, attach the labeled wires to their respective connectors (which each have a paddle you depress and a hole you tuck the correct wire into) and put the supplied AA battery in the rear of the controller. Finally, attach it to the mount, and turn the power back on.

You may have to update the Nest's firmware, and you'll need to use the Google Home app to get it connected to your Wi-Fi network and adjust the basic settings. Once it's up and running, you can also use the small touch-sensitive strip on the right-hand edge of the controller to adjust it.

Set and don't sweat

During setup, you'll be prompted to create routines for your thermostat to control how it changes its temperature during the day. You'll set preferred temperatures for hot and cold weather, and can get granular with timing, down to 15-minute windows. A green leaf will indicate when your chosen temperature settings are eco-friendly — that is, low consumption.

My setup is simple: at 6:45 a.m. the thermostat turns on and warms my apartment to my preferred daytime temperature (72 degrees during winter — I tried the eco-friendlier 68 degrees, but it was too cold). At 10 p.m., it switches to 65 degrees and stays there until the next morning. If I go out (which, granted, these days I almost never do) it drops to 60 degrees until I get home. Of course, if I want to change this, I can do so from anywhere in the world my smartphone has an internet connection.

Just remember not to set [the "away" temperature] too low if you've got pets.

There's also an option called "presence sensing" — which uses the same sensor that wakes the mirror-finish display when you approach it — to check if there's someone home, so they're not stuck with your away temperature. If you live with other people, you can also connect all of your smartphones to Google Home, enable location sharing, and then have the thermostat switch to your "away" temperature automatically when nobody's home. Just remember not to set it too low if you've got pets.

I've also got the thermostat set up in my Google Home routines, so if I tell one of my Google smart speakers I'm going to bed earlier than usual or going out, it'll set the temperature to the corresponding preference.

Smart, but no sensors

Another pair of clever features is the option to use the thermostat section of the Google Home app to get reminders to change your air filters, and the option to let your app nudge you if something seems amiss. For instance, if you leave a door or window open and the temperature isn't climbing as it should be, you'll get a pop-up on your phone to alert you. If the problem is something more significant, you can arrange for a certified technician to come and have a look (at your own expense) straight from the app.

Unlike the fancier Nest Learning Thermostat, there are no connected temperature sensors included, though, and no option to add them down the road. Whether or not that limitation is a problem will depend on your home. If you've got a sprawling pad where the temperature varies a lot in different parts of it, you may find getting your ideal temperatures set will take a little more trial and error. However, if you have multiple thermostat controllers, you can replace them all with Nests and they'll work together perfectly, keeping their respective sectors at the presets you choose.

Cut that bill

The Google Home app includes an "Energy Dashboard" where you can see how long your HVAC system has been on each day, week, or month, and see how your usage increases or decreases from month to month. My utility company, Con Edison, also recently installed smart meters in my building, so I can use its website to check my electricity usage. Sadly, none of this is any use for categorically stating whether the Nest Thermostat is saving me money.

First, I only installed it two months ago, so I only have two months of its data. Second, I've only been in my current apartment since March last year, so I don't have enough historical data for a meaningful comparison. And third, my HVAC uses more electricity in summer because of the central A/C, and more gas in winter for heating, so comparing like with like is even harder.

But even without data I can tell you with relative certainty, it is saving me money. Why? Because the simple act of being able to schedule temperature changes or have them automatically shift based on my location means I'm running the HVAC less than I used to. I always used to forget to adjust it when I went to bed or when I went out. Also, if the Nest Thermostat didn't save money (and resources) utility companies likely wouldn't be offering to subsidize it.

Considering those subsidies, if your system supports a Nest Thermostat, there's no good reason not to get one. It's easy to install, easy to use, almost certainly more attractive than whatever you're using now, and it will pay for itself in short order. Plus, you can use its mirror finish to check you don't have anything in your teeth on the way out the door.