OPERATION
→The Mode button selects the operating mode of the thermo- stat. If OFF is selected, the thermostat will not enter Heating or Cooling mode. If HEAT is selected, the thermostat will only enter Heating mode (if the room temperature is below the heat- ing set point). If COOL is selected, the thermostat will only en- ter Cooling mode (if the room temperature is above the cooling set point). If AUTO is selected, the thermostat will enter Heat- ing or Cooling mode based on the room temperature and the heating and cooling set points. If PROGRAM ON is selected, the thermostat will operate as in the AUTO mode and the stored schedule is enabled. The thermostat will follow the Occupied and Unoccupied schedules stored in its memory.
Auto-Changeover — When the thermostat mode is set to AUTO, the thermostat will provide automatic changeover from Heating to Cooling mode and Cooling to Heating mode when required. The thermostat will automatically switch to maintain the desired temperature setting. The thermostat does not need to be manually changed from heating to cooling or cooling to heating operation.
Two-Stage Operation — The second stage of heat or cool is turned on when the first stage has been on for a mini- mum of 2 minutes and the temperature differential from the set point is equal to or greater than the set point plus the deadband plus 2 degrees.
Clock Backup — In the event of a power loss, the ther- mostat will keep time for a minimum of 48 hours without external power or batteries.
Fan Operation — If Fan On is selected, the fan will run continuously during occupied schedules (except when Mode is switched to OFF). The fan will be off during the unoccupied schedule except during heating or cooling operation.
If Fan On is not selected, the fan will only operate during heating or cooling operation.
Emergency Heat — Emergency heat is available for heat pump applications. To turn on emergency heat, press and hold the Override button. While holding the Override button, press the UP ARROW button. An ‘‘EH’’ will be displayed. During emergency heat, the fan will operate and the second stage of heat will be energized (locking out the first stage com- pressor). To exit emergency heat, press and hold the Override button. While holding the Override button, press the UP ARROW button. During emergency heat, only OFF and HEAT modes are available.
Electric Heat — When the Electric Heat option in the advanced set up is set to ON (configured by installer), the thermostat will turn on the fan immediately any time there is a heat demand. This feature should only be used on electric heat- ing applications. Do not use with gas heat.
Holiday Mode — When the thermostat is in Holiday mode, the thermostat will operate under Unoccupied set points. To configure and activate the Holiday mode, press the Mode and UP ARROW buttons simultaneously to enter Program- ming mode. Press the Override button to enter Holiday Pro- gramming mode. The ‘‘HOL’’ icon will be displayed along with the remaining days of Holiday mode operation. Press the UP or DOWN ARROWS to select the number of days that the holiday schedule will be in effect. A value of 0 disables Holi- day mode. The duration can be set from 1 to 99 days. The ther- mostat will enter Holiday mode on midnight of the next day after the mode has been activated. Holiday mode will remain in effect until midnight of the last configured day.
If the Holiday mode is in effect, the number of days remain- ing will blink on and off and the ‘‘Unoccupied’’ icon will be displayed. The Override button will be active during Holiday mode. The Dry Contact Switch is ignored.
To turn off the Holiday mode before the remaining config- ured days have passed, press the Mode and UP ARROW buttons simultaneously for 2 seconds to enter Programming Mode. Press the Override button to enter Holiday Program- ming mode. Press the DOWN ARROW to set the number of days to zero. Holiday mode will be disabled.
Dry Contact Switch (33CS250-FS Only) — A dry contact switch is provided to allow an external device to force the thermostat into Occupied 1 mode. When the thermostat is forced into Occupied 1 mode via the dry contact closure, the Occupied 1 icon will blink each second.
SOFT START — When multiple thermostats are controlled by the same external device, a Soft Start option can be used to stagger the turn on times of the HVAC equipment. This feature may cause a delay in operation after entering Occupied 1 mode.
Remote Temperature Sensor (33CS250-FS Only) — A remote temperature sensor is available to read the temperature from a space. If a remote temperature sensor is connected and the thermostat is configured to use a remote temperature sensor, then the thermostat will ignore the reading of its internal sensor and control to the reading of the remote temperature sensor. When the thermostat is using a reading from a remote sensor, the degree symbol above the temperature reading will blink.
NOTE: This feature is configured by the installer.
→Outside Temperature Sensor (33CS250-FS Only) — An optional outside temperature sensor may be pro- vided to sense outdoor-air temperature. Press and hold the Mode button for 5 seconds to display outdoor-air temperature. The “outside” temperature annunciator will be displayed. Press the Mode button again to exit the Outside Temperature display.
