Honeywell CT70 Owner's Manual - Page 9

FAN: When this terminal is activated, the fan is on. With the fan switch in the auto position, the fan cycles on and off with the heat pump. With the fan switch in the ON position, the fan is on continuously. MULTIPLE AUX. HEAT LOADS: This terminal is activated when additional auxiliary heat loads are required. Because the CT70 only has provisions for one auxiliary heat load, these loads must be connected to the AUXILIARY HEAT terminal. OUTDOOR SENSOR: This terminal is not connected to the CT70. On your original thermostat, this terminal was activated by an outdoor sensor that controlled the auxiliary heat source. OUTDOOR STAT: Outdoor Thermostat. This terminal is activated when the system switch is in the EM. HT. position. The outdoor thermostat controls the amount of auxiliary heat that is activated. POWER: This terminal connects to the power side of the 24-volt transformer. COMMON: This terminal connects to the common side of the 24-volt transformer. SYSTEM MONITOR: Some heat pumps have the ability to indicate when the heat pump is malfunctioning. When this occurs, this terminal is activated and the EM. HT. LED is activated. 9