Carrier P274-0100-C, P274-0300-C User Manual

OWNER'S

Residential

MANUAL

Part Numbers P274-0100-C, P274-0200-C, P274-0300-C

J IMPORTANT: Read entire instructions before program-ming the thermostat.

GENERAL

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
not required.

OPERATION

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
display.

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).

Non-Programmable

Thermostat

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

selected.
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 displaythe

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
LCD.

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
filtel:

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

REPLACES: 997-510011-19

CATALOG NO. 570-352

Battery Changeout- If the installation requires tile

usage of batteries, the batteries will require replacement every

NOTE: If installation is hard-wired, batteries are not
required and will not need to be replaced.

12 months.

Open thermostat door and slide the battery compartment
door to the fight. Remove two AA alkaline batteries. Install
two new AA alkaline batteries following the polarity markings

Error Codes --If the thermostat displays "--", "E2",

"E3", or "E4" in the LCD, an error is present. See Table 1 for
enor codes and descriptions.

(+ / -) on the thermostat.

Table 1 -- Error Codes

SYMPTOM WHAT TO CHECK
Blank LCD Check for 24 vac between R and C at terminal connections or battery.

"--" (2 dashes) on temperature display Temperature sensor reading out of range. Check sensor for damage. If recycling power

"E2" on temperature display Brownout condition or too low of voltage to thermostat. Double check wiring and check for

"E3" on temperature display The outdoor temperature sensor is open, not connected, or shorted.

"SERVICE FILTER" on temperature display After the selected number of hour of blower operation "FILTER" will display on LCD. This is

Cooling will not come on Select COOL mode. Set desired temperature to 10° F below room temperature. Simulta-

Heating will not come on Select HEAT mode. Set desired temperature to 10° F above room temperature. Simulta-

does not clear display, thermostat should be replaced.

24 vac between R and C. E2 will clear 15 sec after proper voltage is restored.

to remind the home owner to "check" the filter. Press RESET FILTER button to clear display
and reset timer to 0.

neously press FAN and INCREASE TEMPERATURE buttons to defeat timers. Check for
COOL ON icon and 24 vac at Y (first-stage) terminal. If present, thermostat is okay and

3roblem is with equipment or wiring. If not present, replace thermostat.

neously press FAN and INCREASE TEMPERATURE buttons to defeat timers. Check for
HEAT ON and 24 vac at Y (first-stage) terminal (with heat pump) or W/W1 (with air condi-

tioner) terminal. If present, thermostat is okay and problem is with equipment or wiring. If
not present, replace thermostat.