Why does the Smart Thermostat HD (ADC-T40K-HD) setup wizard recommend a different HVAC system than expected?
The Thermostat has mechanical wire detection in the wire terminals, meaning any terminal with a wire inserted will indicate there is a wire present during setup, even if the wire is unused by the HVAC system. Sometimes there are extra, unused wires present within the wire bundle at the wall.
Important: Only insert the wires that have use at the control board into the wire terminals. If necessary, identify the used wires at the HVAC unit and only plug those into the wire terminals. Unused wires should be safely terminated and secured.