Google Nest Learning Thermostat (4th gen) with Nest Temperature Sensor (2nd gen) vs Sensi Touch 2 Smart Thermostat ST76 (Black)
These are side-by-side facts taken from each product guide: published specifications, strengths and caveats as their sources state them. This page is not a test, a ranking or a verdict about which model is better.
Google Nest Learning Thermostat (4th gen) with Nest Temperature Sensor (2nd gen)
Multi-stage 24V systems run through the Google Home app, in homes with or without a C wire
Google's top thermostat, bundled with one room sensor, a trim plate and a steel plate. The maker lists up to three stages of heat and cool, three-stage heat pumps with aux and emergency heat, plus humidifier, dehumidifier and ventilation terminals. Power Sharing means no C wire in most homes, and control runs through Google Home and Matter.
Published specifications
- Maker: most 24V systems; heating and cooling 1-3 stages; heat pump to 3 stages with AUX, AUX2 and E
- Maker: star connector takes only one of W3, Y3, G3, E, HUM or DEHUM; AQ+/AQ- limited to Y3 or VENT/HUM/DEHUM
- Maker: Power Sharing works with or without a C wire; under 1% of homes may need a C wire or Nest Power Connector
- Maker: Wi-Fi 802.11n on 2.4 GHz and 5 GHz; works with Google Home and Matter; Google Home app required to set up
- Maker: 3.9 in diameter, 1.1 in deep, 5.7 oz; 2.7-inch 600x600 circular display; Soli, temperature, humidity, light sensors
- Warranty: Google Store lists 2 years retail and 5 years for HVAC pros; the listing's warranty PDF says one year
Strengths
- Maker publishes the exact stages and terminals, including three-stage heat, cool and heat pump support
- Trim plate, steel plate and a Nest Temperature Sensor are all in the box
- Works without a C wire in over 99% of homes by Google's own figure, and takes 2.4 GHz or 5 GHz Wi-Fi
Caveats
- Setup requires the Google Home app and account; Alexa or Apple control goes through Matter and may need a third-party hub
- Warranty length differs between Google's spec page and the warranty PDF on the listing, and covers authorised resellers only
- The extra terminals are shared: you cannot use W3, Y3, G3, E, HUM and DEHUM all at once
Read the full Google Nest Learning Thermostat (4th gen) with Nest Temperature Sensor (2nd gen) guide
Sensi Touch 2 Smart Thermostat ST76 (Black)
Homes with a C wire and up to 2H/2C or 4H/2C heat pump equipment
Copeland's glass-touchscreen Sensi thermostat, confirmed by matching UPC. It lists 1H/1C, 2H/2C and 4H/2C heat pump staging, humidifier and dehumidifier control, and up to fifteen optional room sensors. Every system needs a C wire. Copeland's page lists 5 GHz Wi-Fi, but the installation guides say 2.4 GHz only.
Published specifications
- Maker: stages 1H/1C, 2H/2C; heat pump 4H/2C; humidification and dehumidification; dual fuel logic
- Listing, spec sheet and guides: C wire required; 20-30 Vac, 24 VAC; batteries not included
- Wi-Fi: maker page 2.4 and 5 GHz; installation guides 2.4 GHz only; Bluetooth LE
- Sensors: up to 15 Sensi room sensors, sold separately; outdoor sensor option for aux lockout
- Maker: 5.60 x 3.25 x 0.77 in; 8 sq in glass touchscreen; spec sheet: Alexa, Google Assistant, SmartThings
- Maker warranty table and spec sheet: 3 years, DIY or professional install
Strengths
- Copeland lists up to 2H/2C conventional and 4H/2C heat pump staging, plus humidity control
- Works with up to fifteen optional Sensi room sensors
- Three-year warranty applies whether you or a contractor installs it
Caveats
- A C wire is required on every system
- Maker page lists 5 GHz Wi-Fi but the installation guides say 2.4 GHz only
- Setup requires the Sensi app, an account and Bluetooth on your phone
Read the full Sensi Touch 2 Smart Thermostat ST76 (Black) guide
How to choose between them
Choose the Google Nest Learning Thermostat (4th gen) with Nest Temperature Sensor (2nd gen) if your situation matches: Multi-stage 24V systems run through the Google Home app, in homes with or without a C wire. Its main caveat: Setup requires the Google Home app and account; Alexa or Apple control goes through Matter and may need a third-party hub.
Choose the Sensi Touch 2 Smart Thermostat ST76 (Black) if your situation matches: Homes with a C wire and up to 2H/2C or 4H/2C heat pump equipment. Its main caveat: A C wire is required on every system.
Both entries repeat what each guide records. Confirm the model, included parts and availability on the current listing before ordering.
Primary sources
- Google Store tech specs and wiring compatibility, Nest Learning Thermostat (4th gen) Source for Google Nest Learning Thermostat (4th gen) with Nest Temperature Sensor (2nd gen)
- Google Consumer Hardware Limited Warranty PDF supplied with the Amazon listing Source for Google Nest Learning Thermostat (4th gen) with Nest Temperature Sensor (2nd gen)
- Google Nest compatibility checker named on the Google Store specs page and in the listing Source for Google Nest Learning Thermostat (4th gen) with Nest Temperature Sensor (2nd gen)
- Copeland product page and specifications for Sensi Touch 2 ST76 Source for Sensi Touch 2 Smart Thermostat ST76 (Black)
- Sensi Touch 2 installation guide R-5556-4 (November 2024) on Copeland's media server Source for Sensi Touch 2 Smart Thermostat ST76 (Black)
- Sensi Touch 2 installation guide R-5556 (August 2022) supplied with the Amazon listing Source for Sensi Touch 2 Smart Thermostat ST76 (Black)
- Sensi Touch 2 spec sheet R-5530 supplied with the Amazon listing Source for Sensi Touch 2 Smart Thermostat ST76 (Black)
- Copeland Sensi warranty table by model Source for Sensi Touch 2 Smart Thermostat ST76 (Black)
Primary sources checked .