Nest Thermostat E vs Nest Learning Thermostat (3rd Gen) full review

Nest manufactures a range of smart home products, but it made its name with its original 'Learning Thermostat'. For years you didn't get much of a choice when buying a Nest thermostat - you simply bought the latest model they'd made - but now the company has introduced the Thermostat E, and for the first time buyers have a choice of Nest thermostats.

Whether you're looking to buy your first Nest, or are debating whether you should swap your 3rd gen Nest for the newer E, here's how the two smart heating systems stack up.

For a more in-depth assessment of each, make sure to read our reviews of the Nest Thermostat E and the 3rd gen Learning Thermostat, or take a look at our smart heating chart to find out about the best rival systems.

Price and availability

Comparing the prices of the two models is surprisingly tricky, because beyond the actual cost of the thermostat you also have to factor in potential installation costs - and to make things even more confusing, the US models - and thus their pricing - are actually slightly different to the UK's, owing to differences in common central heating systems. 

Let's start with the UK. Here, the Nest E is £199, while the regular 3rd gen model is £219. That makes the E cheaper - but not by much.

Still, in the UK you've also got to factor in installation costs: Nest recommends a professional installation for the 3rd gen, but describes the E as 'easy to install yourself', meaning you could save on expert installation - priced at £120 on Amazon right now. We're not convinced it's that simple though - installation of the two devices isn't as dissimilar as Nest would have you believe, negating the savings from the E.

Things are simpler in the US at least. There the E costs just $169, with the regular Learning Thermostat at $249 - enough of a price difference that the E inarguably represents a major saving. Both are very similar to install, so neither has more of a need for professional help than the other, so the decision will mostly come down to whether the 3rd gen's extra features are worth that $80 difference.

Compatibility

Depending on your home heating system, you may not have a choice to make anyway: after all, if only one of the two Nest models is compatible with your boiler, then you'll be stuck with that one.

The good news is, both Nests claim to be compatible with most systems. The UK advice is that both 'work with most central heating systems', while the US is slightly more specific: the E 'works with 85% of 24V heating and cooling systems', while the 3rd gen is compatible with 95% of those systems.

Either way, it pays to be safe, so head to the Nest website and use its compatibility checker to be certain which thermostat you can use.

Design and build

While both Nests look pretty similar on the surface, there are actually some major differences - and, once again, a confusing divide between the UK and US models.

The 3rd gen Learning Thermostat is essentially the same no matter where you buy it. It's a round circular device with an LED display which you mount onto the wall in place of your existing thermostat. The metallic finish is available in a range of colours: white, black, copper, and stainless steel in the UK; and all of those plus mirror black, polished steel, and brass in the US.

The colour display will tell you the current temperature in your home, along with the thermostat's target temperature and handy info like how long it will take for your home to heat up to get there. Round the outside of the body is a dial which you can rotate to adjust the temperature - making a surprisingly satisfying clicking sound that's actually produced by a speaker, rather than anything mechanical.

The Thermostat E has a lot of similarities, and a few big differences - especially in the UK. First up, here's what the same: it's an almost identical round design with a colour display in the centre, and an exterior dial that you rotate. 

In the US, you'll mount this on the wall, just as you would with the Learning Thermostat - which is why installation is essentially identical. In the UK it's a little different, as what you install on the wall is actually a grey fabric-covered disc called the Heat Link E, and the thermostat itself sits elsewhere in your home, mounted on a small stand.

In either country, the thermostat has a few other aesthetic differences. It's only available in white, and has a matt polycarbonate finish, rather than metallic. The display is also different: it's lower resolution (though that hardly matters) and comes with a frosted finish, which helps it blend into the walls a little more, rather than glaring out brightly. It's a very clever design touch that for us gives the E a big edge on the regular Nest.

Installation

If you're in the US, you can mostly ignore this section. Installation of either Nest device is almost identical, and quick enough to do at home so long as you're comfortable with a screwdriver and a bit of re-wiring. You should't need professional help to install either - though it is of course available if you're a total DIY-phobe.

Once again, in the UK it's a little trickier. The Thermostat E installation is roughly similar to the two US models: the bulk of the work consists of unscrewing your old thermostat from the wall, identifying and disconnecting the wires, and re-wiring them appropriately into the Heat Link E, which you then mount and wirelessly connect to the thermostat itself. It takes an hour or so to install, and is easy enough - again, assuming you're happy with a screwdriver and learning how to read some electrical diagrams.

The regular Nest is a trickier installation job in the UK, which is why Nest recommends professional installation - but in all honesty it mostly requires the same skills as the E. You'll need to connect a Heat Link up to your boiler, in addition to replacing your thermostat, but once again this mostly just involves unscrewing some bits and moving some wires. The voltages can be higher, but as long as you switch the power off before you begin, this shouldn't really be all that much harder than installing the Thermostat E.

It really comes down to this: if you're totally terrified of DIY, then you'll want to pay for professional installation of either model. If you're comfortable with it, you'll probably be fine installing either of them yourself. It's going to be a very small subset of people who can set up the E but find the regular model too much, and in the UK that's the only way the E looks like a substantially better option.

Features

So what are the differences between the two models when it comes to features?

Um, not very much really, which is the biggest argument in favour of the cheaper model, especially in the US. Both thermostats connect to your phone and/or smart assistant to let you control the heating (and cooling in the States), with the ability to set schedules, learn from your behaviour, and adjust based on whether you're at home or not.

The main feature difference is Farsight, which allows the tech to spot you across the room and activate to show the time, weather, and temperature. The E misses out on this - and its screen won't tell you the time or weather - but it will still activate when you walk past the thermostat, which is almost as good. Farsight is the definition of a 'nice-to-have', and it's hard to imagine anyone deciding it's worth $80.

There's another difference in the UK though: here the regular Nest is capable of controlling your hot water supply, while the E isn't. That's a potentially significant difference for some users, and could well be enough to justify the pricier model, even if it brings with it the cost of installation.

Is the Thermostat E an upgrade?

Luckily this one's easy: no. 

The E isn't a lot worse than the regular Learning Thermostat - as we've said, it's only missing Farsight, and hot water control in the UK - but equally it isn't really any better. If you already have a 3rd gen Nest device you won't see any appreciable benefit from switching to the E unless you really love that frosted display.

Which Nest should you buy?

Which Nest you should buy depends a lot on where you are. In the US, the E is almost a no-brainer: it's $80 cheaper, offers almost exactly the same features, and takes the same effort to install. The only reasons to prefer the 3rd gen are the Farsight display and potentially the colour options (though actually we prefer the finish on the E). Otherwise, the E is essentially the same thing for a lot less money.

In the UK it's much trickier. The devices themselves are almost the same price, so the only saving comes from skipping professional installation costs. As we've argued above, it's not clear that the E really is substantially easier to install though, and we suspect that most of the people who'd want to pay for installation with the 3rd gen would also opt to pay for it with the E.

At that point you're only saving £20, and the option to control your hot water alone is worth that much, making the 3rd gen a better bet unless you're a huge fan of the E's frosted finish.