Honeywell CT3550 Owner's Manual - Page 17

STEP 11. SET THE FAN AND SYSTEM KEY Set the Fan Key Fan On: The fan runs continuously. Use for improved air circulation or more efficient central air cleaning. (In a heat only system, the fan runs continuously only if the fan relay is connected to the G thermostat terminal). Press Fan until display shows On. Fan Auto: Normal setting for most homes. The equipment controls the fan operation. Press Fan until display shows Auto. NOTE: If you set the fan to On during normal operation, the fan reverts to the programmed fan setting when the next program period begins. Set the System Key Heat: The thermostat controls your heating system. Press System until display shows Heat. Off: Both the heating and air conditioning systems are off. Press System until the display shows Off. Cool: The thermostat controls your air conditioning system. Press System until the display shows Cool. 17 69-1284-2