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Part Numbers P274-0100-C, P274-0200-C, P274-0300-C
J IMPORTANT: Read entire instructions before program-ming the thermostat.
Tot_dine® thermostats are wall-mounted, low-voltage ther-
mostats which maintain room temperature by controlling the
operation of an HVAC (heating, ventilation trod air condition-
ing) system. Sepm'ate heating and cooling set points and
auto-changeover capability allow occupied and unoccupied
programming for energy savings.
During power interruption the internal memory stores tem-
perature and mode settings for an unlimited time. Batteries are
Thermostat Display -- The thermostat display is locat-
ed in the top center of the thermostat. See Fig. 1. The following
information can be displayed on the screen:
• mode (OFF. HEAT. COOL, EHEAT, or AUTO)
• fan setting (ON or AUTO)
• auxiliary heat status (P274-0200-C, -0300-C only)
• room temperature
• desired temperature
• reset tilter
• outdoor temperature (P274-0200-C, -0300-C only)
Thermostat Buttons --The thermostat has buttons
which are used to change the set points of the thermostat and
set the thermostat modes. The buttons are accessible from
behind the thermostat covel: To access the buttons, pull on the
hinged thermostat covel: The buttons ;ue: MODE, FAN, and
RESET FILTER. See Fig. 1.
The UP and DOWN buttons are used to change the cunent,
desired temperature set point and to scroll through program-
ming set points. The UP and DOWN buttons am located on the
fi'ont of the thermostat.
Setting Indoor Temperature Set Points
1. Press the UP or DOWN button one time. The LCD
(liquid crystal display) will illuminate and the current
temperature set point will be displayed. Next to the
temperature display, HEAT or COOL will be dis-
played. SET TEMP will appear above the temperature
2. To change the temperature set point, continue to press
the UP or DOWN buttons until desired temperature is
reached. Press the MODE button to set temperature for
another setting (Heat or Cool).
3. The thermostat will automatically return to regular
operation within 5 seconds.
NOTE: The cool setting must be at least 2 degrees higher than
the heat setting for proper operation.
Fan Operation -- 33_e FAN button selects fan operation.
The fan can operate in either Fan ON or AUTO mode.
Press the FAN button to switch between fan ON or AUTO
mode. When the fan is set to ON, "FAN" is displayed in the
LCD on the thermostat. The fan will mn continuously for im-
proved air circulation while in the ON position.
When the fan is set to AUTO mode, the fan runs only as
needed to maintain indoor air temperature.
NOTE: The "FAN" indicator will not be displayed in the LCD
when thermostat is operating in AUTO mode.
Mode Operation -- The Mode button selects the operat-
ing mode of the thermostat. Pressing the MODE button will
rotate the following options on the LCD: OFF. HEAT. COOL,
AUTO, and EHEAT (heat pump models only). The mode
for each selection will be displayed on the thermostat when
NOTE: If AUTO is selected, the thermostat will enter Heating
or Cooling mode based on the room temperature and the heat-
ing and cooling set points.
Display Outdoor Temperature -- To display the
outdoor-air temperature on thermostats offering this feature,
simultaneously press the UP and DOWN buttons for twenty
seconds. The outdoor temperature will then be displayed on the
NOTE: Two dashes "--" appearing on the LCD indicates that
the thermostat either does not have this feature installed or the
temperature sensor is not properly connected.
Reset Filter Display -- The thermostat will display
"FILTER" on the LCD when it is time to change or clean the
After cleaning or changing the filter, press the RESET
FILTER button to restart the timer and turn off the indicator
Auto Changeover Operation -- 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
fi_)m heating to cooling or cooling to heating operation.
Manufacturer reserves the right to
discontinue, or change at any time,
specifications or designs without notice
and without Incurring obllgaUons.
REPLACEMENT COMPONENTS DIVISION
©CARRIER CORPORATION 2004 9-04
PRINTED IN U.S.A.
LITERATURE NUMBER P274-7SO
CATALOG NO. 570-352