It is not possible to say no. If you already own an ecobee4 and would like to purchase a new model, our thermostat models are compatible with each other. You don't need to replace your ecobee4 to use the SmartThermostat with voice control. Upgrading from an ecobee3 lite to SmartThermostat with voice control is the same thing.
Let's Get It Fixed!
HomeX virtual experts will assess your issue (for free!) and can resolve simple problems.