Abstract: An air conditioning system thermostat includes a visual display and plural switch actuators, respectively backlit by an electroluminescent lamp and LED light sources mounted on a circuit board disposed in a thermostat housing. A control circuit causes at least one switch actuator to be illuminated continuously and the light sources for the display and the remaining switch actuators are illuminated in response to actuation of any one of the switch actuators. Switch contact elements mounted on the switch actuators and the circuit board provide advantageous positioning of the LED light sources for the switch actuators. An energy savings switch actuator allows the control circuit to directly assume setback temperature settings in response to a first actuation and a second actuation resets the thermostat to the initial user set temperature settings.