A thermostat that is configured to be releasably secured to a wall mountable connector, wherein the wall mountable connector includes a jumper switch that permits an installer or other professional to easily form an electrical connection between different wiring terminals of the wall mountable connector in accordance with how particular field wires are connected to the wiring terminals of the wall mountable connector. The thermostat is further configured to automatically determine the position of the jumper switch of the wall mountable connector, and in some cases, change the control of at least some functionality of the thermostat and/or HVAC equipment depending on the position of the jumper switch.