Many thermostats are programmable, but what makes the Nest Learning Thermostat special is its ability to learn your lifestyle and program itself. After installation, adjust your temperature as you normally would, and after a few days the Nest starts to predict your habits and will make sure the temperature is what you want when you want it. Let's say you usually turn up the temperature when you get home from work - soon, the Nest will learn how long it takes to heat your home, and make sure the temperature is ideal when you walk in the door. The stylish 3rd generation Nest Learning Thermostat is packed with even more features than its predecessor, including a 40% larger screen with a brighter, sharper display. It also gives you control over your hot water system, letting you set schedules and boost production when needed, and is now compatible with OpenTherm boilers. Create individual heating zones by placing up to 20 thermostats in a home, and control up to two homes from one Nest account.

From your first look at the display, it's clear that the Nest is designed to elevate your home climate management. Farsight uses 150° far-field activity sensors to detect if anyone is in the room, and if so, displays the time, temperature, or current weather. Ambient light sensors ensure the screen is always the correct brightness for the atmosphere. "Time to Temp" lets you see exactly how long until your desired temperature is reached. Tap the display for Quick View to get a status summary, access settings and schedules, and view energy history. The Nest Leaf icon indicates when you're actively saving energy, and the app will give you a monthly overview to show how much you've saved. The rotating bezel lets you quickly adjust the temperature or scroll through options. The Nest Learning Thermostat works seamlessly with other Nest products; for example, it can shut off your boiler if smoke or carbon monoxide is detected by your Nest Protect.

What makes the Nest Learning Thermostat so advanced? In addition to learning your schedule, it uses multiple sensors and algorithms to ensure maximum comfort and efficiency. Ten individual temperature sensors track the temperature and how long it takes to change. When connected to WiFi, it takes the weather forecast into account. The Sunblock feature detects when the thermostat is in direct sunlight, and automatically adjusts itself - extremely useful when using air conditioning in the summer. True Radiant takes into account the extra time needed to warm your home, and prevents overshooting the desired temperature by activating and shutting the boiler off early. Eco Temperature uses a motion sensor to determine if anyone is home and lowers the temperature when you're away. You can even set it to track the location of your family's smart devices for more accuracy. And for those occasional extremely cold days, Safety Temperature will automatically turn on the heat to keep your pipes from freezing, and send you a notification if your heating system can't keep up.

The Nest app is compatible with Apple devices running iOS9 and Android devices running Android 4.1 or later. The web app is compatible with the latest version of Safari, Chrome, Firefox, or IE on Mac OS X v10.9 and Windows 7 or later. It's also available on smart watches; both Apple Watch OS 2 and Android Wear 5.1.1 or later. One Nest app controls all of your Nest devices. An active WiFi connection is required. On the app home screen, you will see an overview of all your Nest thermostats. From there, you can access scheduling, hot water controls, and Eco Temperature mode. Additionally, you can connect multiple devices to the thermostat so the whole family has control. No need to share a login; each person can create their own Nest account.

The Nest Learning Thermostat measures 8.4 cm in diameter and 3.2 cm in depth. It has a sharp 24-bit colour LCD display, with 480x480 resolution at 229 ppi, and a diameter of 5.3 cm. It is compatible with most heating systems, including combi boilers, system and heat-only boilers, domestic hot water tanks, hydronic underfloor systems, air source and ground source heat pumps (heating only), zoned systems, and heating systems with OpenTherm. You can connect it to your existing thermostat wiring, or use it wirelessly and place it anywhere - it has a rechargeable lithium ion battery. The Nest thermostat connects to your boiler using the Heat Link (included), which needs to be installed on your boiler by a professional. The Nest will not work without the Heat Link, because it converts the standard 230V to 12V for better efficiency. Including the Heat Link, the Nest Learning Thermostat only uses 2 kWh per month. To control the system remotely, you will need an active WiFi connection, the Nest app, and the latest version of Safari, Chrome, Firefox, or IE on Mac OSx v10.9 or later, or Windows 7 or later. It can connect to 2.4GHz or 5GHz WiFi networks (802.11b/g/n). The Heat Link requires a 802.15.4 @ 2.4GHz WiFi connection.