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C-Wire Check product 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.

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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

Fit and limits

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

What the ST76 is, and what is in the box

The Sensi Touch 2 ST76 is a glass-touchscreen Wi-Fi thermostat sold under Copeland's Sensi brand. Copeland's product page shows UPC 786710566547, the same code as the Amazon listing, and model number ST76, so the identity is confirmed. Copeland lists it at 5.60 inches long, 3.25 inches high and 0.77 inches deep, with an eight-square-inch touchscreen.

Copeland's box list is the thermostat, instructions, mounting hardware, wire labels and a warranty document, and its specification says batteries are not included. The listing's Included Components field names an installation guide, warranty booklet, thermostat, mounting hardware and owner's manual. Room sensors, wallplates and the thermostat guard are separate accessories on the spec sheet.

Every system needs a C wire

This is the first thing to check. The listing bullet says a common wire is required, and the spec sheet states that all systems require a common wire. Both versions of the installation guide say Sensi Touch 2 requires a c-wire to power the thermostat, and the 2022 guide says it will not turn on without 20 to 30 volts AC between R and C.

The 2022 and 2024 installation guides add that on a heat-only system you may be able to install an external transformer, and point to Sensi's support site for that option. Copeland rates the unit at 20 to 30 volts AC and 24 VAC. Use Sensi's compatibility check before buying; we give no wiring steps here.

Stages, accessories and sensors Copeland lists

Copeland's specification lists single stage 1H/1C, multi-stage 2H/2C and heat pump 4H/2C, and the spec sheet lists single and multi-stage gas, oil and electric systems and single and multi-stage heat pumps. The installation guide's wiring pages show a two-stage heat pump with first and second-stage auxiliary or emergency heat. Copeland also lists humidification, dehumidification and dual fuel logic control.

The guide describes an accessory terminal pair for one-wire or two-wire accessories selected by a switch on the thermostat. Copeland lists indoor and outdoor sensor options, and says an outdoor sensor provides temperature for auxiliary heat lockout. The description says you can pair up to fifteen Sensi room sensors, sold separately; the room sensor guide gives the same fifteen-sensor limit.

The Wi-Fi band claims conflict

Copeland's current product page lists Wi-Fi 2.4 GHz and Wi-Fi 5 GHz, and the Amazon description mentions 2.4 and 5.0 GHz connections. But both installation guides, including the November 2024 revision, tell you to make sure your network is 2.4 GHz and say Sensi is only compatible with 2.4 GHz networks. The listing's spec sheet says 2.4 GHz Wi-Fi.

We are not going to decide which is right. If your router only offers a 5 GHz network, ask Sensi support before buying, or plan on a 2.4 GHz network being available. Setup also needs the Sensi app, an account linked to your email address, and Bluetooth permission on your phone to connect the thermostat to Wi-Fi.

App, account, voice and privacy

The installation guide says you must use the Sensi app to install and configure the thermostat, and that anyone with your account email and password can control every thermostat on it. The spec sheet lists Amazon Alexa, Google Assistant and SmartThings, and Copeland's page lists seven-day programming with up to eight periods a day and geofencing.

The listing includes a privacy statement about how Sensi handles personal information, and it mentions about 23 percent HVAC energy saving. We did not read the basis for that figure for this model, so treat it as a listing claim. We did not read the app terms or privacy policy.

Warranty terms and what to confirm

Copeland's warranty table lists ST76 models among its DIY models with three years of coverage whether you or a professional contractor installs it. The spec sheet says the thermostat includes a three-year limited warranty, and the Amazon warranty field says three years. These all agree; we did not read the full written warranty text.

Before ordering, confirm two things: that you have a C wire or a plan for one, and that a 2.4 GHz network is available given the conflicting band statements. Ask Sensi for the written warranty terms if you need details on remedy or proof of purchase.

Check the current listing

Check this model on Amazon

Confirm the model, included parts and availability before ordering.

Primary sources

  1. Copeland product page and specifications for Sensi Touch 2 ST76
  2. Sensi Touch 2 installation guide R-5556-4 (November 2024) on Copeland's media server
  3. Sensi Touch 2 installation guide R-5556 (August 2022) supplied with the Amazon listing
  4. Sensi Touch 2 spec sheet R-5530 supplied with the Amazon listing
  5. Copeland Sensi warranty table by model

Primary sources checked .

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