
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
PC 111 Catalog No. 533-348 Printed in U.S.A. Form 33CS-32SI Pg 4 105 8-00 Replaces: New
Book 1 4
Ta b 1 1 a 1 3 a
Copyright 2000 Carrier Corporation
2. Press the Mode button. The current temperature will be
displayed.
3. Use an accurate thermometer to measure room tempera-
ture. Press the UP or DOWN ARROW buttons until the
number equals room temperature.
4. Press the Mode button to return to normal operation.
Check Thermostat Operation — To check thermo-
stat operation, perform the following procedure:
1. Press the Mode button repeatedly until the Heat icon ap-
pears on the display. The thermostat is now in Heating
mode.
2. Press the UP ARROW button until the heating set point is
10 F (6 C) higher than the current room temperature
Heating and fan should be energized.
3. Press the Mode button repeatedly until the Cool icon ap-
pears on the display. The thermostat is now in Cooling
mode.
4. Press the DOWN ARROW button until the cooling set
point is 10 F lower than the current room temperature.
Cooling and fan should be energized.
5. If heating, cooling, or fan operation do not energize,
check wiring and consult Table 3.
Final Checklist
1. Put away tools and instruments. Clean up debris and
packaging.
2. Review Owner’s Guide with occupant or owner. 3. Leave
the manuals with owner.
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.
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.
Fan Operation — If Fan On is selected, the fan will run
continuously (except when Mode is switched to OFF).
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. This option is only available if
Advanced Setup Step 1 (Heat Pump) is set to ON. To turn on
emergency heat, press and hold the UP button. While holding
the UP button, press the Fan 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 compressor). To exit emergency heat, press and hold
the Fan button. While holding the Fan button, press the UP but-
ton. During emergency heat, only OFF and HEAT modes are
available.
Electric Heat — When the Electric Heat option in the ad-
vanced setup is set to ON (configured by installer), the thermo-
stat will turn on the fan immediately any time there is a heat
demand. This feature should only be used on electric heating
applications. Do not use with gas heat.
Keypad Lock — To prevent unauthorized use of the ther-
mostat, the front panel buttons can be disabled. To disable or
lock the keypad, press and hold the Mode button. While hold-
ing down the Mode button, press the UP and DOWN ARROW
buttons simultaneously. The ‘‘Locked’’ icon will appear on the
display.
The thermostat is unlocked by performing the same proce-
dure. Press and hold the Mode button. While holding down the
Mode button, press the UP and DOWN ARROW buttons si-
multaneously. The ‘‘Locked’’ icon will be removed from the
display.
TROUBLESHOOTING
Table 3 — Troubleshooting
PROBLEM SOLUTION
Display on thermostat not illuminated. Check for 24 vac at the R terminal connection. Terminal R must be connected for proper
thermostat operation.
Cooling will not energize. Select COOL mode. Decrease cooling set point to 10 degrees below room temperature.
Check for 24 vac at Y1 terminal with a load connected. If present, thermostat is operating
correctly and problem is with wiring or equipment. If 24 vac is not present, replace the
thermostat. Check for Compressor Cycle per Hour Limit. Cooling may be locked out.
Heating will not energize. Select HEAT mode. Increase heating set point to 10 degrees above room temperature.
Check for 24 vac at W1/O/B terminal with a load connected. If present, thermostat is oper-
ating correctly and problem is with wiring or equipment. If 24 vac is not present, replace
the thermostat.
When using 4 wires (R,G,W,Y), the cooling equipment tries
repeatedly to turn on, but cannot. At times the display dims or
disappears.
There is not enough power available. Connect a 270 ohm, 10 watt power resistor at the air
conditioning equipment between terminals W and C (non-heat pump applications only).
When using 4 wires (R,G,W,Y), the heating equipment tries
repeatedly to turn on, but cannot. At times the display dims or
disappears.
There is not enough power available. Connect a 270 ohm, 10 watt power resistor
at the air-conditioning equipment between terminals Y and C (non-heat pump applications
only).
When controlling a heat pump, heat comes on during cooling cycle. Configure thermostat for heat pump operation (Table 2, Step 1).
When calling for cooling, both heating and cooling are energized. The thermostat is configured for a heat pump. Configure the thermostat for non-heat
pump operation (Table 2, Step 1).
When controlling a commercial heat pump unit, unit runs in reverse
or heating is always on.
Some commercial heat pumps require that Heat Pump Option on thermostat is turned
OFF. Refer to unit installation instructions for more information.
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