Abstract: An environmental controller arranged to control an environmental control system and a method of setting the operational configuration of such an environmental controller are described. The method comprises: displaying a user query from a series of user queries on a display of a user interface on the environmental controller, receiving in response to the at least one user query, a user input at the user interface, the user input relating to at least one of the one or more appliances intended to be controlled by the environmental controller, determining an expected connection configuration for physical connection terminals on the environmental controller based on the user input, and then detecting by the controller connections at the plurality of physical connection terminals; and validating the user input by comparing the detected connections to the physical connection terminals with the expected connection configuration.