Honeywell CT70 Owner's Manual - Page 8

DEFINITIONS OF TERMINAL FUNCTIONS Each terminal of the CT70 controls a different heat pump function. Here is a list of the possible heat pump functions: Function Definition FIRST STG. HEAT: When this terminal is activated, the heat pump is on and heating the living space. AUXILIARY HEAT: When this terminal is activated, the auxiliary heating source is on because the heat pump is unable to meet the heating demand of the living space. FIRST STG. COOL: When this terminal is activated, the heat pump is on and cooling the living space. COMPRESSOR: When this terminal is activated, the heat pump is on and either heating or cooling the living space, depending on the system switch position. C/O VALVE HEAT: Heating Changeover Valve. This terminal is activated when the system switch is in the HEAT position. It provides changeover in heat pumps that change over in heating. C/O VALVE COOL: Cooling Changeover Valve. This terminal is activated when the system switch is in the COOL position. It provides changeover in heat pumps that change over in cooling. EM. HEAT: 8 Emergency Heat. This terminal is activated when the system switch is in the EM. HT position. In this situation, the heat pump is not activated.