The manufacturer’s installation guide identifies Touch 2 models in the ST76 and 1F96U-42WF series. Read the full model on the device or packaging rather than relying on a listing photograph.

Enter the actual existing terminal labels into the supported Sensi compatibility process. Confirm whether the equipment is a conventional system or heat pump and whether additional stages or accessories are involved. Do not use wire colour as a substitute for terminal identification.

Touch 2 requires a common connection for all supported system types. A loose spare wire behind the wall is not automatically usable: the other end and the correct equipment connection must be established. If that work is unclear, ask an HVAC professional to handle it.

Line-voltage electric heating, proprietary communicating equipment and other unsupported systems need a different solution. Do not apply household mains voltage to this low-voltage controller.

Install the legitimate Sensi app and use the account intended to own the thermostat. Have a suitable screwdriver and the supplied mounting hardware ready. Record the home Wi-Fi name and password without putting them into a public photograph.

Use the app’s New Installation route and select the correct product. Keep the original thermostat and its parts until the new installation has been commissioned. A clear photograph of the original terminals is valuable if support needs to understand the previous arrangement.

Choose a time when loss of heating or cooling will not create an urgent household problem. If you have a heat-sensitive occupant or severe weather, professional installation can be the more sensible plan.

The manufacturer’s advertised installation time assumes a suitable starting situation. Adding common wiring, diagnosing old equipment or repairing a damaged wall can change the work considerably. I would plan for the actual installation rather than a marketing timer.

Turn off the heating and cooling equipment supply before handling thermostat wires, following the equipment instructions. An Off setting on the thermostat is not electrical isolation. If you cannot establish a safe working condition, stop.

Remove the old cover using its specified method. Photograph the terminal labels and every connected conductor before disconnecting them. Capture both labels where an old base prints different markings for conventional and heat-pump operation.

The app asks which terminal labels have connected wires. Use those connections rather than guessing from the insulation. If the app reports an invalid configuration, resolve it before proceeding.

The Touch 2 installation instructions say not to transfer the old external jumper wires because the Sensi has its own internal jumper arrangement. Follow the model-specific guide rather than copying every visible piece of the old base. Keep the old arrangement documented for rollback.

Label the conductors individually and keep them from falling into the wall. Remove the old base only after documentation is complete. Mount the Touch 2 base securely using the supplied hardware and the guide’s directions.

Insert each labelled conductor into the terminal assigned by the verified app-guided configuration. Do not create an improvised universal wiring map from this article; terminal requirements depend on the equipment you identified earlier.

The official Touch 2 installation guide should remain beside you for the actual connection and configuration. Check that the common connection is functional at both ends and that no loose conductor can bridge adjacent terminals.

Fit the cover correctly, restore any equipment panels and then restore power as directed. If the screen remains blank, investigate the supply and C-wire arrangement. Do not repeatedly pull wires with the equipment powered.

At the thermostat, open Menu and Wi-Fi. Follow the Sensi app’s connection route for Touch 2. The device displays a QR code; the supported setup also offers a PIN alternative when you do not use the camera.

Bluetooth helps provision this model, so the phone needs the relevant Bluetooth permissions. Choose the supported 2.4 GHz home network and enter its password. Keep the phone nearby while the process completes.

Do not confuse the setup PIN with the router password. They identify different stages: pairing the correct device and joining the home network. If scanning fails, use the app’s documented manual alternative instead of deleting the thermostat immediately.

After registration, confirm that the app shows the intended home and thermostat. An installer should not remain the only person who can control a homeowner’s device. Set up authorised household access using the supported account-sharing arrangements.

Review the system configuration before testing. Heat-pump type, reversing-valve behaviour and auxiliary heat need to match the equipment. A thermostat can be online yet configured incorrectly.

Test the relevant heating, cooling and fan functions using the guide and equipment’s permitted operating conditions. Allow protection delays to finish; do not repeatedly change modes to force a compressor to start. If heating produces the wrong response or auxiliary heat behaves unexpectedly, stop and verify configuration.

Set a sensible schedule, check the displayed temperature and show the household how a temporary override works. Make sure a permanent hold has not accidentally replaced the intended timetable.

Keep the old wiring photograph, new model number and commissioning notes. My recommendation is to finish only when the equipment responds correctly from both local controls and the app—not when the thermostat merely appears in the device list.