A thermostat includes a wiring terminal having a moveable component that is actuatable to enable insertion of an HVAC system conductive wire within the wiring terminal. Insertion of the HVAC system conductive wire within the wiring terminal electrically connects the wiring terminal and the HVAC system conductive wire. The actuation of the moveable component opens a loop of an electrical circuit that does not include the HVAC system conductive wire. The loop may enable power harvesting for the thermostat.