Best Google Smart Thermostat Accessories: 4 Models Compared

Quick picks

Our 4 picks

1 Best overall

Google Nest Temperature Sensor (2nd Gen)

Best for: targeting comfort in specific rooms

Accessory Type

Room temperature sensor

System Compatibility

Nest Learning (3rd/4th Gen), Nest E

Power Source

Battery (up to 3 years)

Sensor Functions

Temperature

Mounting Type

Wall, shelf

Control Method

Google Home or Nest app

View on Amazon: Google Nest Temperature Sensor (2nd Gen) Affiliate link

This room sensor targets comfort in specific areas of your home. It measures temperature and sends data to your Nest Learning Thermostat (3rd or 4th Gen) or Nest Thermostat E. You control it via the Google Home or Nest app. The device runs on a battery that lasts up to three years. You can place it on a wall or shelf in up to six rooms to balance hot and cold spots.

Pros

• Battery lasts up to 3 years
• Works with Nest Learning 3rd/4th Gen and Nest E
• Supports up to 6 sensors for room averaging
• Easy setup via Google Home or Nest app

Cons

• Measures temperature only, not humidity
• Requires compatible Nest thermostat, not standalone
• Sold individually or in packs of 3

Good fit if

• You have a Nest Learning or Nest E thermostat
• You want to fix hot or cold spots in specific rooms
• You prefer app-based scheduling over manual adjustments

Skip if

• You use a non-Nest smart thermostat
• You need humidity monitoring capabilities
• You want a sensor with a built-in display

Verdict: Google Nest Temp Sensor 2nd Gen helps you balance temperatures in up to six rooms. It is the right choice if you already own a compatible Nest thermostat and want precise control over specific areas of your home.

2 Best premium

Google Nest Power Connector C-Wire Adapter

Best for: Nest thermostats in 24 VAC systems

Accessory Type

C wire adapter

System Compatibility

Nest thermostats, 24 VAC systems

Power Source

24 VAC

Mounting Type

Furnace, air handler, zone controller

Dimensions

0.57 × 2.12 × 2.87 inches

View on Amazon: Google Nest Power Connector C-Wire Adapter Affiliate link

The Google Nest Power Connector supplies C wire power to Nest thermostats when your system lacks one. It mounts directly to your furnace air handler or zone controller. This adapter works only with 24 VAC systems. It does not support millivolt or high voltage setups. The unit measures 3.98 inches long and operates between -22°F and 140°F. It suits homes with heating-only, cooling-only, or heat pump systems needing reliable power.

Pros

• Mounts to furnace air handler or zone controller
• Works with 24 VAC systems
• Operates from -22°F to 140°F
• Made with 46% post-consumer recycled materials

Cons

• Incompatible with millivolt systems
• Incompatible with high voltage systems
• Requires mounting inside HVAC equipment

Good fit if

• You have a 24 VAC heating or cooling system
• You need to power a Nest thermostat without a C wire
• You have access to your furnace air handler

Skip if

• You use a millivolt heating system
• You use a high voltage system
• You want a wireless temperature sensor

Verdict: The Google Nest Power Connector Snow provides essential power for Nest thermostats in compatible 24 VAC systems. It fits homeowners who can mount the adapter to their air handler and lack a C wire.

3 Best budget

Google Nest Thermostat Trim Kit

Best for: clean wall coverage for Nest Thermostat installs

Accessory Type

Trim kit

System Compatibility

Nest Thermostat

Mounting Type

Wall, electrical box

Programmability

Programmable

Connectivity

Wi-Fi

Dimensions

7.09 × 4.41 × 0.27 inches

View on Amazon: Google Nest Thermostat Trim Kit Affiliate link

This trim kit covers wall imperfections left by old thermostats. It includes a snow-colored trim plate and a steel mounting plate. The kit fits the Nest Thermostat and measures 4.41 by 7.09 inches. You get mounting screws and an installation card. It suits you if you want a clean look after upgrading your smart thermostat.

Pros

• Includes a steel plate for electrical box mounting
• Matches Nest Thermostat snow color
• Covers wall imperfections from old units
• Includes all necessary mounting screws

Cons

• Only compatible with the Nest Thermostat model
• Does not include a temperature sensor
• Requires wall mounting screws for installation

Good fit if

• You are replacing an old thermostat with visible wall damage
• You own a Nest Thermostat and want a clean finish
• You need a steel plate for electrical box mounting

Skip if

• You use a non-Nest smart thermostat
• You want to control room temperature remotely
• You need a wireless temperature sensor

Verdict: Google Nest Thermostat Trim Kit Snow covers wall gaps and matches your device color. It fits you if you want a tidy install for your Nest Thermostat.

4 Also great

Google Nest Wireless Temperature Sensor

Best for: Nest thermostat owners needing room-specific control

Accessory Type

Temperature sensor

System Compatibility

Nest Learning 3rd Gen, Nest E

Power Source

CR2 3V lithium battery

Connectivity

Bluetooth Low Energy

Sensor Functions

Temperature

Mounting Type

Wall, shelf

View on Amazon: Google Nest Wireless Temperature Sensor Affiliate link

This wireless temperature sensor extends your Nest thermostat’s reach. It connects via Bluetooth Low Energy and uses a single CR2 lithium battery for up to two years of operation. You can place it in specific rooms like nurseries or living areas. The Nest app lets you prioritize readings from up to six sensors. It is ideal for homes with uneven heating or cooling.

Pros

• Bluetooth Low Energy wireless connection
• Up to 2-year battery life on CR2 cell
• Supports up to 6 sensors per thermostat
• Prioritize room temperature in Nest app
• Compact 0.8-inch width design

Cons

• Limited to Bluetooth Low Energy range
• Only compatible with Nest Learning and Nest E
• Requires Nest app for all configuration

Good fit if

• You need to prioritize temperature in a specific room
• You have a Nest Learning or Nest E thermostat
• You want to add multiple sensors to one system

Skip if

• You use a thermostat brand other than Google Nest
• You need Wi-Fi connectivity for remote access
• You require compatibility with third-party smart home hubs

Verdict: Google Nest Temperature Sensor (2nd Gen) is a practical add-on for Nest Learning and Nest E owners who need better temperature control in specific rooms. It fits users who want to prioritize comfort in areas like nurseries or living rooms.

Specifications side by side

Google Smart Thermostat Accessories: 4 Models Compared

Google offers accessories for wiring and room sensing. The Nest Power Connector helps thermostats in 24 VAC systems without a C wire. The Nest Temperature Sensor balances heat in up to six rooms. These tools address specific power and comfort needs.

Other options focus on installation aesthetics. The Trim Kit covers wall gaps for a clean look. It connects via Wi-Fi. The Wireless Sensor provides room-specific control for existing Nest owners. Choose based on your wiring status and room layout.

Where Google Fits Your Home

Google’s range focuses on precise control and clean installation. You can choose from small wireless sensors for room-specific comfort to wall-mounted power connectors for wiring solutions. The lineup includes compact white units and snow-colored trim kits that cover wall gaps. Shapes are mostly rectangular or circular, with minimal profiles. Note that this list does not include smart hubs, remote controls, or advanced lighting accessories. If you need those items, you must look elsewhere. These tools complement existing Nest thermostats rather than replacing them.

How to Choose the Right Google Accessory

1. Match Sensor to Thermostat

   Verify that your chosen temperature sensor works with your existing Nest model. The Google Nest Temperature Sensor (2nd Gen) is designed for precise control in up to six rooms, making it ideal if you already own a compatible Nest thermostat. Check the product specifications to ensure your current device supports remote sensing. This compatibility ensures the sensor can communicate effectively with your main unit to balance temperatures across different areas of your home.

2. Check Power Requirements

   Determine if your system lacks a common wire. The Google Nest Power Connector provides essential power for Nest thermostats in compatible 24 VAC systems. If you cannot mount a C wire to your air handler, this adapter fills that gap. Review the voltage specifications of your HVAC system before purchasing. Ensuring your system is 24 VAC compatible is critical for this accessory to function correctly without requiring professional rewiring.

3. Assess Wall Coverage Needs

   Consider the aesthetic outcome of your installation. The Google Nest Thermostat Trim Kit covers wall gaps and matches the device color for a tidy look. This accessory fits users who want a clean finish for their Nest Thermostat install. Check the dimensions of the kit against the hole in your wall. The snow-colored finish helps it blend seamlessly with most interior decor while providing necessary coverage for exposed wiring or uneven surfaces.

4. Verify Wireless Connectivity

   Ensure the accessory supports wireless communication with your thermostat. The Google Nest Wireless Temperature Sensor connects via Wi-Fi to provide room-specific control. This feature allows you to prioritize comfort in specific areas like nurseries or living rooms. Confirm that your home network supports the required frequency for reliable data transmission. Wireless sensors offer flexibility in placement, allowing you to position them away from the main thermostat for accurate readings.

5. Review Physical Dimensions

   Check the size and weight of each accessory for your installation space. The Nest Temperature Sensor measures 2.18 inches in width and weighs 1.31 ounces, fitting easily in most rooms. The Power Connector has specific width and height requirements for mounting near your air handler. Comparing these physical specifications helps you determine if the accessory will fit your available space without obstructing other components or requiring additional modifications to your setup.

Frequently asked questions

See also

• google nest temperature sensor vs nest temperature sensor
• google nest power connector review
• best google smart thermostats
• best space heater accessories with thermostat