Nest Learning Thermostat 3rd vs 4th Generation

By Naila Syifa
Updated August 2024

Nest Learning Thermostat 3rd vs 4th Generation

Nest Learning Thermostat (4th Generation) succeeded the previous 3rd Generation model with improved features and capabilities. What are these upgrades and are they worth the extra investment? Let's compare both models and find out!

Key Takeaways

The 4th Gen Nest Learning Thermostat has a larger display and 4 new features: Dynamic Farsight, Adaptive Eco, Natural Heating/Cooling, and Smart Ventilation. The 4th Gen Nest has a new backplate that supports ventilation systems and simultaneous humidifier AND dehumidifier connection, compared to the 3rd Gen Nest which only supports humidifier OR dehumidifier. The 4th Gen also now supports Matter.

Nest Learning Thermostat 3rd vs 4th Generation
Nest Learning Thermostat (3rd Generation)

Nest Learning Thermostat (3rd Generation)

Advanced Comfort & Energy-Saving

✓ 2.1” Display with Farsight
✓ Auto-Schedule & Eco Temperature
✓ HVAC Monitoring
✓ 10 Wiring Terminals

Nest Learning Thermostat (4th Generation)

Nest Learning Thermostat (4th Generation)

The Smartest, Most Advanced

✓ 2.7” Display with Dynamic Farsight
✓ Smart Schedule & Adaptive Eco
✓ Matter-Compatible
✓ 12 Wiring Terminals

#1 Price

Nest Learning Thermostat 3rd Generation vs 4th Generation

Nest Learning Thermostat (4th Generation)

At US$279, the Nest Learning Thermostat (4th Generation) is priced only $30 higher than its predecessor, making it a great pick for those who are new to the Nest thermostats. The 3rd Generation Nest, on the other hand, costs US$249, which is cheaper but lacks some of the advanced features found in the newer 4th Generation model.

If you already own the 3rd Generation and are considering an upgrade, the answer to whether the new features are worth the extra investment depends on your specific needs and preferences.

#2 Design & Display

Nest Learning Thermostat 3rd Generation vs 4th Generation

Nest Learning Thermostat (3rd Generation)

Nest Learning Thermostat (4th Gen) introduces a totally new design that looks more premium and aesthetically pleasing. It features a circular liquid crystal display and a slim stainless steel ring that seamlessly blends into the wall. The display is borderless and is significantly larger than the 3rd Generation Nest, measuring 2.7 inch in diameter with a high 600 x 600 pixels resolution.

Nest Learning Thermostat (3rd Gen) has a smaller, bordered 2.1-inch display with 480 x 480 resolution. While it also looks sleek and modern, the metal ring is quite thick and makes the thermostat appear significantly protruding from the wall, making the 4th-generation design look more flush and seamless.

The 4th Generation Nest comes in 3 metal finishes — Polished Silver, Polished Obsidian, and Polished Gold — while the 3rd Generation Nest is available in a wider color variant — Stainless Steel, Copper, White, Black, Brass, Polished Steel, and Mirror Black.

Nest Learning Thermostat 3rd Generation vs 4th Generation

Nest Learning Thermostat (4th Generation) with Dynamic Farsight

Both the 3rd and 4th Gen Nest Learning Thermostats offer Farsight, which means the thermostat's sensor can detect you coming closer and wake up the display to show you important information like the time, temperature, or weather. The sensors being used for this feature are different, with the 4th Gen model using a more advanced Soli sensor compared to the proximity & motion sensors on the 3rd Gen Nest.

Thanks to the Soli sensor, the 4th Gen Nest has an upgraded Dynamic Farsight, displaying different information based on your distance to the thermostat. If you're further away, the display will only show a single piece of information, but as you approach, it will provide more detailed information about weather, outdoor air quality, humidity, or others.

The good news is that all of these are customizable, so you can choose what you want the 4th Generation Nest Learning Thermostat to display at different distances.

Another design element important to consider is the control interface. Settings and adjustments on both thermostats can be done by rotating the dial. The difference is that when pressed down, the Nest Learning Thermostat (4th Gen) can also show a more detailed description of what the thermostat is doing in the background.

#3 System Compatibility

Nest Learning Thermostat 3rd Generation vs 4th Generation

4th Gen Nest Adds AQ Terminals

Both the 3rd Generation and 4th Generation Nest Learning Thermostats are compatible with a wide range of HVAC systems, including heating, cooling, heat pump, fan, power, humidifier, and dehumidifier. They also don't need a common (C) wire to work.

The 4th Gen Nest Learning Thermostat features a new 12-terminal backplate, adding 2 extra wiring terminals compared to the 10 on the third-gen model. These two extra terminals (AQ+ and AQ-) allow the 4th Gen Nest to work with a ventilation system, which the 3rd Generation Nest Learning Thermostat could not support.

These additional terminals also allow for more flexible installation of a humidifier and dehumidifier. As a comparison, the Nest Learning Thermostat (3rd Gen) only has one star * terminal compatible with a humidifier or dehumidifier, so we can only choose either one to connect to the thermostat.

Meanwhile, the new AQ terminals in the 4th Gen Nest Learning Thermostat can be connected to a humidifier/dehumidifier/ventilation. In this case, we can connect both the humidifier and the dehumidifier to the thermostat simultaneously by leveraging both the * and AQ terminals.

Real Case Example
Nest Learning Thermostat (3rd Gen)
🔹 Humidifier -> 1 humidifier on *
🔹 Dehumidifier -> 1 dehumidifier on *

Nest Learning Thermostat (4th Gen)
🔹 Humidifier & dehumidifier -> 1 humidifier on * and 1 dehumidifier on AQ
🔹 Humidifier & dehumidifier -> 1 dehumidifier on * and 1 humidifier on AQ
🔹 Humidifier & ventilation -> 1 humidifier on * and 1 ventilation on AQ
🔹 Dehumidifier & ventilation -> 1 dehumidifier on * and 1 ventilation on AQ

In sum, the new AQ terminals allow the 4th Gen Nest to support ventilation systems and support a simultaneous connection of humidifiers AND dehumidifiers, unlike the 3rd Gen Nest Learning Thermostat which could only choose either humidifiers OR dehumidifiers.

#4 Features

Nest Learning Thermostat 3rd Generation vs 4th Generation

Schedules in the Google Home app

Nest 'Learning' Thermostat lives up to its name, automatically learning your temperature preferences and creating a personalized schedule to keep you comfortable while also saving energy. Note that the learning process can take some time, so manual adjustment during the initial learning period is very important.

Try to change the temperature on a habitual basis, such as when you wake up, leave the house, come home, and go to bed. This will help the thermostat to understand your preferences and routine. If you're not satisfied with the auto schedule programmed by the thermostat, you can manually make adjustments.

The Smart Schedule in the 4th Generation Nest will also try to identify potential schedule changes and make energy-saving suggestions, which you can accept or reject in the Google Home app. You can choose whether you want adjustments to be automatically made or require manual approval.

Nest Learning Thermostat 3rd Generation vs 4th Generation

Nest Learning Thermostat (4th Generation)

To further save energy bills, both the Nest Learning Thermostat 3rd Generation and 4th Generation can be set up to automatically run an energy-efficient temperature when it senses nobody's home. This feature is known as 'Eco Temperature', which is configurable in the Home/Away settings on both thermostats.

The difference is that the 3rd Generation Nest will start switching back to the comfort temperature only when it detects someone returning home, while the 4th Generation Nest offers an enhanced Adaptive Eco feature that can ensure returning the desired comfort temperature within one hour of your arrival.

Adaptive Eco uses weather conditions to find the perfect Eco Temperature, so when you're away, the thermostat will keep the temperature within one hour of your desired comfort level. As a result, you can come home feeling comfortable more quickly than having to wait for the thermostat to slowly adjust back to your preferred temperature.

For instance, if your Eco Temperature for heating is 50°F, your comfort temperature is 70°F, and it's very cold outside, Adaptive Eco might keep your home's temperature to 60°F when you're away. This way, it can easily return to the 70°F comfort level within one hour of you getting home. Adaptive Eco can also be disabled if you want to prioritize energy savings over quick comfort.

Nest Learning Thermostat 3rd Generation vs 4th Generation

Potential Issue Notification

Another similar feature that both thermostats offer is the ability to detect and notify you of potential issues on the HVAC system. For example, if your cooling system is turned on but your home gets warmer, the thermostat will alert you that there may be a problem with your air conditioner. This feature is known as 'System Health Monitor' on the 4th Gen Nest and 'HVAC Monitoring' on the 3rd Gen.

Both the Nest Learning Thermostat 3rd Generation and 4th Generation work with Nest Renew, which can help to shift energy use to cleaner or cheaper times. They also work with Nest Temperature Sensor to extend temperature monitoring and control to other rooms in your home, but the 3rd Gen requires a separate purchase while the 4th Gen Nest includes the 2nd Gen Nest Temperature Sensor in the box.

Nest Learning Thermostat (4th Gen) has more advantages with 2 new features that relate to sensing environmental conditions: Natural Heating/Cooling and Smart Ventilation.

Natural Heating/Cooling feature senses outdoor temperature so it can adjust the heating or cooling system to save energy, such as pausing heating when it detects warmer weather during winter.

Smart Ventilation feature senses outdoor air quality and will adjust ventilation accordingly to maintain healthy indoor air quality, such as disabling ventilation when outdoor air quality is poor. Note that this feature requires a compatible ventilation system.

#5 Setup & Installation

Nest Learning Thermostat 3rd Generation vs 4th Generation

Nest Learning Thermostat (3rd Generation)

The 3rd and 4th Generation Nest Learning Thermostats are designed to have easy DIY installation. A Trim Kit is also included to cover any wall imperfections if needed

The setup is also a straightforward process, guided by the step-by-step instructions in the app. One little difference is that the Nest Learning Thermostat 4th Gen uses the Google Home app for setup, whereas the 3rd Gen Nest uses the Nest app.

After the initial setup in the Nest app, the 3rd Gen Nest Learning Thermostat can also be controlled with the Google Home app if you want, but a migration process may be required.

Nest Learning Thermostat (4th Gen) is also now Matter-compatible, which means it can be seamlessly integrated with a wider range of smart home devices and platforms beyond just Google or Nest's ecosystem. The 3rd Gen, on the other hand, has not yet provided support for Matter.

Nest Learning Thermostat 3rd vs 4th Generation

Final Thoughts

Nest Learning Thermostat 3rd Generation vs 4th Generation

Nest Learning Thermostat (4th Generation)

The 4th Generation Nest Learning Thermostat is a big leap forward in terms of design, features, and system compatibility over the 3rd Generation model.

The new Adaptive Eco, Natural Heating/Cooling, and Smart Ventilation make the 4th Generation Nest a far more intelligent thermostat that can adapt to your routines and home's needs more effectively. The new Matter support and AQ terminals on the backplate also expand its compatibility and integration options.

If you are looking for the most advanced and versatile Nest Learning Thermostat that can help you save energy and maintain the most comfortable indoor climate, the 4th Generation model can be a worthy, future-proof investment.

If you like to read more about Smart Thermostats, check out our other relevant guides here:

Best Smart Thermostats

Google Nest Learning Thermostat 3rd Generation Review

Ecobee vs Nest Thermostat

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