System compatibility is first
A thermostat designed for one HVAC/control type may not work with another.
Power and wiring matter
Some thermostats need specific conductors or accessories.
Smart features vary
Schedules, occupancy logic, remote sensors and energy reports are not standardized across brands.
Installation can cross a technical boundary
HVAC controls should be installed according to manufacturer instructions and appropriate professional requirements.
Keep in mind. Compatibility is not permanent. Confirm the current manufacturer, platform and certification information before purchasing, resetting or migrating a device.