The SC2211 is a multi-stage, heat pump thermostat for 24 VAC systems. The thermostat activates the heat pump when the room temperature is below the heat set temperature (by the differential temperature). Auxiliary heat will be activated if the room temperature continues to drop. Third stage heat is activated (on some systems) if the temperature drops further. The heat outputs are staged off (configurable, setting 5) as the room temperature increases. The thermostat will not let the compressor come on for four minutes after it turns off. This protects your compressor. When the room temperature is greater than the cool set temperature (by the differential temperature), the cooling device is activated. Second-stage cooling will be activated if the room temperature continues to rise. The cool outputs are staged off (configurable, setting 5) as the room temperature decreases. The thermostat will not let the compressor come on for four minutes after it turns off. This protects your compressor. The SC2211 has the following operating modes: OFF, Heat, Emergency Heat and Cool. In OFF mode, the thermostat will not turn on heating or cooling devices. In the Heat mode, the thermostat controls the heat pump system. In the Emergency Heat mode, the heat pump is bypassed and auxiliary becomes the primary heat source. In the Cool mode, the thermostat controls the cooling system. The indoor fan can be turned on in all operating modes using the Fan switch. Features ?For heat pumps only ?3 stage heat/2 stage cool ?Single compressor heat pump system with auxiliary heat ?New ICM patented Thermal Intrusion Barrier ?Large display with backlight ?Adjustable temperature differential ?Zoning system compatible ?Hardwired ?Anti-short cycle time: 4 minutes ?Manual changeover ?Easy access terminal block ?Precise temperature sensing ?Soft touch controls ?Keypad lockout ?Status LEDs