Carrier AC Instructions and recipes

Non-Programmable Thermostats
Installation, Start-Up, and Operating Instructions
NOTE: Read the entire instruction manual before starting the
installation.
This symbol →indicates a change since the last issue.
SAFETY CONSIDERATIONS
Read and follow manufacturer instructions carefully. Follow all
local electrical codes during installation. All wiring must conform
to local and national electrical codes. Improper wiring or installa-
tion may damage thermostat.
Recognize safety information. This is the safety-alert symbol .
When you see this symbol on the equipment and in the instruction
manual, be alert to the potential for personal injury.
Understand the signal words DANGER, WARNING, and CAU-
TION. These words are used with the safety-alert symbol. DAN-
GER identifies the most serious hazards which will result in severe
personal injury or death. WARNING signifies a hazard which
could result in personal injury or death. CAUTION is used to
identify unsafe practices which would result in minor personal
injury or product and property damage.
INTRODUCTION
Carrier thermostats are wall-mounted, low-voltage thermostats
which maintain room temperature by controlling the operation of
a heating and air conditioning system. Separate heating and
cooling setpoints, plus auto changeover provide maximum comfort
and flexibility. Batteries are not required; temperature and mode
settings are preserved with the power off.
INSTALLATION CONSIDERATIONS
Power
Note that all thermostat models require no batteries and are not
"power stealing". They do require 24vac (both R and C terminals)
to be connected for proper operation. Thermostat will not operate
without these 2 connections.
Models
There are 3 different models. The 9th and 10th letters of the part
number indicate the model. These 2 letters also appear on the
package and on the circuit board. Be sure to have the proper
thermostat for the intended application. Models are:
AC — 1-stage cool, 1-stage heat for AC systems only.
HP — 1-stage cool, 2-stage heat for either HP, or AC with 2-stage
heat.
2S — 2-stage cool, 2-stage heat for 2-speed AC systems, or
2-stage cool, 3-stage heat for 2-speed HP systems.
Use each only for its intended purpose. See Table 1.
INSTALLATION
Step 1—Thermostat Location
Thermostat should be mounted:
• Approximately 5 ft (1.5m) from floor.
• Close to or in a frequently used room, preferably on an inside
partitioning wall.
• On a section of wall without pipes or duct work.
Thermostat should NOT be mounted:
• Close to a window, on an outside wall, or next to a door leading
to the outside.
• Exposed to direct light and heat from a lamp, sun, fireplace, or
other temperature-radiating object which may cause a false
reading.
• Close to or in direct airflow from supply registers and return-air
grilles.
• In areas with poor air circulation, such as behind a door or in
an alcove.
Step 2—Select Model and Jumper
AC Model (1-stage cool, 1-stage heat) is to be used for single-
stage heating and/or cooling applications only. It CANNOT be
used with optional outdoor temperature sensor. (See Table 1 and
Fig. 2, 3, and 4.)
HP Model (1-stage cool, 2-stage heat) can be used with a
single-speed heat pump (HP), or an air conditioner (AC) with a
2-stage furnace or fan coil. A resistor (R19) serves as a HP/AC
selector jumper. This thermostat comes configured from the
factory as a heat pump thermostat. Leave R19 installed for HP
operation. Cut and discard for AC operation. When AC operation
is selected, the O/W2 terminal is converted from a reversing valve
output (O) to a second-stage heat output (W2). This output can be
used to control 2-stage furnaces or 2-stage electric heat in fan coils.
(See Table 1 and Fig. 5, 6, and 15.)
2S Model is for 2-speed compressor HP and AC systems only.
Output Y1 controls compressor low speed and output Y/Y2
controls compressor high speed. Jumper resistor R19 serves as
HP/AC selector exactly as described above for HP model. (See
Table 1 and Fig. 8 through 13, 16 and 18.)
HEIGHT (IN.) WIDTH (IN.) DEPTH (IN.)
3-1/2 5-3/4 1-3/8
Fig. 1—Carrier Non-Programmable Thermostat
A94134
®
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Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 4
Tab misc. misc. PC 101 Catalog No. 03TS-TA1 Printed in U.S.A. Form TSTAT-14SI Pg 1 5-97 Replaces: TSTAT-11SI

Step 3—Install Thermostat
Before installing thermostat, turn off all power to unit. There
may be more than 1 power disconnect. Electrical shock can
cause personal injury or death.
1. Turn OFF all power to unit.
2. If an existing thermostat is being replaced:
a. Remove existing thermostat from wall.
b. Disconnect wires from existing thermostat, 1 at a time. Be
careful not to allow wires to fall back into the wall.
c. As each wire is disconnected, record wire color and
terminal marking.
d. Discard or recycle old thermostat.
NOTE: Mercury is a hazardous waste and MUST be disposed of
properly.
3. Open thermostat rear door (mounting base) to expose mount-
ing holes. The base can be removed to simplify mounting.
Snap apart carefully at hinge to separate mounting base from
remainder of thermostat.
4. Route thermostat wires through large hole in mounting base.
Level mounting base against wall (for aesthetic value
only—thermostat need not be leveled for proper operation)
and mark wall through 2 mounting holes.
5. Drill two 3/16-in. mounting holes in wall where marked.
6. Secure mounting base to wall with 2 anchors and screws
provided, (additional anchoring holes available for more
secure mounting if needed) making sure all wires extend
through hole in mounting base.
7. Adjust length and routing of each wire to reach proper
terminal and connector block on mounting base with 1/4 in. of
extra wire. Strip only 1/4 in. of insulation from each wire to
prevent adjacent wires from shorting together when con-
nected.
8. Match and connect equipment wires to proper terminals of the
connector blocks. (See Table 1 and Fig. 2 through 24.) Both R
and C must be connected for proper thermostat operation.
Improper wiring or installation may damage the thermostat.
Check to make sure wiring is correct before proceeding with
installation or turning on unit.
9. Push any excess wire into wall and against mounting base.
Seal hole in wall to prevent air leaks. Leaks can affect
operation.
10. Snap hinge back together.
11. Close thermostat assembly making sure pins on back of circuit
board align with sockets in connector.
12. Turn ON power to unit.
On power up, LCD readout will display AC, HP, A2, or H2
depending on the thermostat model and jumper status.
Step 4—Set Thermostat Configuration
Configuration options, like the R19 configuration jumper are
intended to be selected at installation and are normally not
modified by the homeowner. These options are not discussed in the
Homeowner’s Guide and therefore must be made as part of the
installation. A special procedure allows entry into the configura-
tion mode. The thermostat will automatically exit this mode if no
button is pressed for 1 minute. While in the configuration mode, 6
option choices can be made:
1. Anticipator—Value Adjustment.
2. Zoning ON/OFF—Selection.
3. Fahrenheit/Celsius—Selection.
4. Clean Filter Timer—Selection and Value Adjustment.
5. G (Fan) ON with any W (Heat)—Selection.
6. High-Ambient Auxiliary Heat Lockout—Selection and Value
Adjustment.
An explanation for each of these and how to enter the configura-
tion mode follows.
To enter the configuration mode:
Press and hold the FAN button for approximately 10 sec until
room temperature disappears and display reads "1-". You are now
in the configuration mode.
NOTE: If the FAN button is pressed again or if no button is
pressed for 60 sec, the thermostat will exit the configuration mode
and return to normal operation. To re-enter the configuration
mode, the FAN button must be pressed and held for 10 sec again.
While in configuration mode, these option choices are available:
ANTICIPATOR—VALUE ADJUSTMENT
This adjustment controls the sensitivity and cycle rate of the
thermostat. Higher numbers decrease the sensitivity and slow the
cycle rate. Lower numbers increase sensitivity and increase cycle
rate. However, a limiting feature will not allow more than 4
equipment cycles per hr, regardless of setting. Values can range
from 1 to 9. Factory default setting is 3. This default selection will
provide optimum performance in nearly all installations. Try it
first. Do not change setting unless there is evidence of need to do
so.
Unlike conventional anticipators, this setting is not to be deter-
mined by current draw. There is no need to measure, know, or
compensate for current. There is also no droop with this thermo-
stat, regardless of anticipator setting. This adjustment controls only
sensitivity and cycle rate up to the maximum of 4 cycles per hr.
TO ADJUST:
1. Enter configuration mode (if not already there).
2. Use up and down buttons to display 1-.
Table 1—Model Selection and Wiring Diagram Chart
OUTDOOR UNIT AIR CONDITIONER HEAT PUMP
1 Speed 2 Speed 1 Speed 2 Speed
1-Stage
Furnace Model AC See Fig. 2 Model 2S See Fig. 8 Requires Dual Fuel Thermostat Model 2S See Fig. 11
2-Stage
Furnace Model AC See Fig. 3 Model HP See Fig. 5 Model 2S See Fig. 9 Requires Dual Fuel Thermostat Model 2S See Fig. 12
Typical Fan Coil Model AC
See Fig. 4 Model HP See Fig. 6 Model 2S See Fig. 10 Model HP See Fig. 7 Model 2S See Fig. 13
FK4C Fan Coil Model AC
See Fig. 14 Model HP See Fig. 15 Model 2S See Fig. 16 Model HP See Fig. 17 Model 2S See Fig. 18
2

3. Press MODE button once to display current value between 01
and 09. Factory default is 03.
4. Use up and down buttons to move between values.
5. Press MODE button to return to 1-. Up and down buttons now
move between option choices 1- through 6-. Or press FAN
button to exit configuration mode.
ZONING ON/OFF—SELECTION
This selection enables or defeats the 4 cycles per hr limit and the
5 minute timeguard. These timers MUST be enabled for normal
operation and disabled for zoning applications. In zoning applica-
tions, the zone control center performs these timing functions.
TO SELECT:
1. Enter configuration mode (if not already there).
2. Use up and down buttons to display 2-.
3. Press MODE button once to display current selection of ON or
OF (OFF). Factory default is OFF.
4. Use up and down buttons to move between ON and OFF.
Select ON for zoning applications ONLY and OFF for all
other applications.
5. Press MODE button to return to 2-. Up and down buttons now
move between option choices 1- through 6-. Or press FAN
button to exit configuration mode.
FAHRENHEIT/CELSIUS—SELECTION
This selection operates the thermostat in either Fahrenheit or
Celsius. Factory default is Fahrenheit.
TO SELECT:
1. Enter configuration mode (if not already there).
2. Use up and down buttons to display 3-.
3. Press MODE button once to display current selection of F or
C. Factory default is F.
4. Use up and down buttons to move between F and C.
5. Press MODE button to return to 3-. Up and down buttons now
move between option choices 1- through 6-. Or press FAN
button to exit configuration mode.
CLEAN FILTER TIMER—SELECTION AND VALUE AD-
JUSTMENT
Select hr of blower operation (heating, cooling, or fan) before
CLEAN FILTER icon is displayed. With OFF selected, icon will
never come on, disabling this feature. Time selection can be from
400 to 3600 hr by selecting numbers 1 through 9. (Time is 400 X
number selected.) Factory default is 2 (800 hr). Recommended
selections are: disposable filter 400 to 800 hr, media filter 1200 to
1600 hr, or electronic air cleaner 1600 to 2400 hr of blower
operation.
TO SELECT or ADJUST:
1. Enter configuration mode (if not already there).
2. Use up and down buttons to display 4-.
3. Press MODE button once to display current selection of OF, 1,
2, 3, 4, 5, 6, 7, 8, 9, or L. Factory default is 2. ("L" has no
function; do not select.)
4. Use up and down buttons to move between available choices.
5. Press MODE button to return to 4-. Up and down buttons now
move between option choices 1- through 6-. Or press FAN
button to exit configuration mode.
G (FAN) ON WITH ANY W (HEAT)—SELECTION
This selection determines whether the G (fan) output is to be ON
or OFF when any W (furnace or strip heat) output is ON. Most
furnaces and fan coils manage their own blowers and do not
require a separate G signal. For these applications, select OFF.
Some auxiliary heaters require a separate G signal to turn on the
blower. In this case, select ON. Factory default is OFF.
TO SELECT:
1. Enter configuration mode (if not already there).
2. Use up and down buttons to display 5-.
3. Press MODE button once to display current selection of ON or
OFF. Factory default is OFF.
4. Use up and down buttons to change between ON and OFF.
5. Press MODE button to return to 5-. Up and down buttons now
move between option choices 1- through 6-. Or press FAN
button to exit configuration mode.
HIGH-AMBIENT AUXILIARY HEAT LOCKOUT − SELEC-
TION AND VALUE ADJUSTMENT
Present in HP and 2S models only when configured as a heat
pump. Outdoor temperature sensor must be attached. This selec-
tion allows lockout of any electric heat (W output) when outdoor
temperature is above a selected temperature. Temperatures of 15˚
to 55˚F (or equivalent values in C) can be selected. Feature can be
disabled by selecting OFF. Emergency heat (EHEAT mode)
always overrides this feature.
TO SELECT or ADJUST:
1. Enter configuration mode (if not already there).
2. Use up and down buttons to display 6-.
3. Press MODE button once to display current selection of OF,
15, 20, 25, 30, 35, 40, 45, 50, or 55. Factory default is OFF.
4. Use up and down buttons to move between available choices.
5. Press MODE button to return to 6-. Up and down buttons now
move between option choices 1- through 6-. Or press FAN
button to exit configuration mode.
Thermostat configuration is now completed.
Step 5—Fan, Mode, Reset Filter Button Operation
1. Pressing FAN button will select AUTO or ON fan operation.
Fan annunciator displays current selection.
2. Pressing MODE button will select OFF, HEAT, COOL,
AUTO. Heat pumps will also have an EHEAT mode. Mode
annunciator displays current selection.
3. Pressing RESET FILTER button will reset filter timer. An-
nunciator will display CLEAN FILTER on LCD display after
the selected number of hr of blower operation. This will
remind homeowner to clean or replace filter.
Step 6—Check Thermostat Operation
FAN OPERATION
1. Press FAN button, starting fan operation. Fan annunciator
switches from AUTO to ON.
2. Press FAN button, stopping fan operation. Fan annunciator
switches from ON to AUTO.
HEATING OPERATION
1. Press MODE button until HEAT is displayed under the mode
annunciator.
2. Press up button until LCD readout reads 10˚F above room
temperature. Heating system should begin to operate within 5
minutes.
COOLING OPERATION
1. Press MODE button until COOL is displayed under the mode
annunciator.
3
→
→
→

2. Press down button until LCD readout reads 10˚F below room
temperature. Cooling system should begin to operate within 5
minutes.
Step 7—Checklist
1. Run equipment through several heating and cooling cycles to
ensure proper operation.
2. If equipment is to be left in operation, BOTH heating and
cooling desired temperature settings as well as operating mode
must be properly selected. Refer to Homeowner’s Guide for
procedure.
3. Put away tools and instruments, and clean up debris.
4. Review Homeowner’s Guide with owner.
5. Leave literature packet with owner.
→Fig. 2—Single-Speed Air Conditioner
with Single-Stage Furnace
A97237
24 VAC HOT

24 VAC COMM

HEAT STAGE 1

COOL STAGE 1

FAN
R
C
G
W/W1
Y/Y2
R
CC
MODEL AC
THERMOSTAT SINGLE-STAGE
FURNACE SINGLE-SPEED
AIR CONDITIONER
G
W
YY
→Fig. 3—Single-Speed Air Conditioner
with 2-Stage or Variable-Speed Furnace
A97238
24 VAC HOT

24 VAC COMM

HEAT STAGE 1

COOL STAGE 1

FAN
R
C
G
W/W1
Y/Y2
R
CC
MODEL AC
THERMOSTAT TWO-STAGE OR
VARIABLE-SPEED
FURNACE SINGLE-SPEED
AIR CONDITIONER
See note 1
G
Y
W/W1
Y
W2
A97239
→Fig. 4—Single-Speed Air Conditioner
with Typical Fan Coil
24 VAC HOT

24 VAC COMM

HEAT STAGE 1

COOL STAGE 1

FAN
R
C
G
W/W1
Y/Y2
R
CC
Y
MODEL AC
THERMOSTAT TYPICAL FAN COIL SINGLE-SPEED AIR CONDITIONER
See notes 5 and 10
Y/Y2
G
*
*
W2
Y1
O
L
E
*
*
W3
A97123
→Fig. 5—Single-Speed Air Conditioner
with 2-Stage or Variable-Speed Furnace
24 VAC HOT

24 VAC COMM

HEAT STAGE 1

COOL STAGE 1

FAN
R
C
G
W/W1
Y/Y2
R
C
W2
C
Y
MODEL HP
THERMOSTAT TWO-STAGE OR
VARIABLE-SPEED
FURNACE SINGLE-SPEED
AIR CONDITIONER
See notes 2 and 3
W/W1
Y/Y2
G
HEAT STAGE 2

N/A

N/A

OUTDOOR

SENSOR

CONNECTION
Y1
B
S1
S2
O/W2
4

→Fig. 6—Single-Speed Air Conditioner
with Typical Fan Coil
A97124
24 VAC HOT

24 VAC COMM

HEAT STAGE 1

COOL STAGE 1

FAN
R
C
G
W/W1
Y/Y2
R
C
HEAT STAGE 2

N/A

N/A

OUTDOOR

SENSOR

CONNECTION
Y1
B
S1
S2
C
Y
MODEL HP
THERMOSTAT TYPICAL FAN COIL SINGLE-SPEED AIR CONDITIONER
See notes 2, 3, 5, and 10
Y/Y2
G
O/W2
*
*
W2
Y1
O
L
E
*
*
W3
→Fig. 7—Single-Speed Heat Pump
with Typical Fan Coil
A97125
24 VAC HOT

24 VAC COMM

HEAT STAGE 2
R
C
G
W/W1
Y/Y2
R
C
RVS COOLING

N/A

RVS HEATING

OUTDOOR

SENSOR

CONNECTION
Y1
B
S1
S2
O
C
Y
MODEL HP
THERMOSTAT TYPICAL
FAN COIL SINGLE-SPEED
HEAT PUMP
See notes 5, 6, and 10
Y/Y2
G
O/W2
*
*
W2
R
W2
O
Y1
E
L
*
*
W3
COOL/ HEAT 
STAGE 1
FAN
→Fig. 8—Two-Speed Air Conditioner
with Single-Stage Furnace
A97126
24 VAC HOT

24 VAC COMM

HEAT STAGE 1

COOL STAGE 2

FAN
R
C
G
W/W1
Y/Y2
R
C
N/A

COOL STAGE 1

N/A

OUTDOOR

SENSOR

CONNECTION
Y1
B
S1
S2
C
MODEL 2S
THERMOSTAT SINGLE-STAGE
FURNACE TWO-SPEED
AIR CONDITIONER
See notes 2 and 4
G
O/W2
W
R
YY2
L
Y1
→Fig. 9—Two-Speed Air Conditioner
with 2-Stage or Variable-Speed Furnace
A97127
24 VAC HOT

24 VAC COMM

HEAT STAGE 1

COOL STAGE 2

FAN
R
C
G
W/W1
Y/Y2
R
C
HEAT STAGE 2

COOL STAGE 1

N/A

OUTDOOR

SENSOR

CONNECTION
Y1
B
S1
S2
C
MODEL 2S
THERMOSTAT TWO-STAGE OR
VARIABLE-SPEED
FURNACE TWO-SPEED
AIR CONDITIONER
See notes 2, 3, 4, and 5
G
O/W2
R
Y2
L
W/W1
Y/Y2
W2
Y1
Y1 *
5

→Fig. 10—Two-Speed Air Conditioner
with Typical Fan Coil
A97128
24 VAC HOT

24 VAC COMM

HEAT STAGE 1

COOL STAGE 2

FAN
R
C
G
W/W1
Y/Y2
R
C
HEAT STAGE 2

COOL STAGE 1

N/A

OUTDOOR

SENSOR

CONNECTION
Y1
B
S1
S2
O
C
Y1
MODEL 2S
THERMOSTAT TYPICAL
FAN COIL TWO-SPEED
AIR CONDITIONER
See notes 2, 3, 4, 5, and 10
Y/Y2
G
O/W2
*
*
W2
R
Y2
Y1
E
L
*
*
W3
L
→Fig. 11—Two-Speed Heat Pump
with Single-Stage Furnace
A97129
24 VAC HOT

24 VAC COMM

HEAT STAGE 3

COOL/HEAT
STAGE 2

FAN
R
C
G
W/W1
Y/Y2
R
C
RVS COOLING

COOL/HEAT
STAGE 1

RVS HEATING

OUTDOOR

SENSOR

CONNECTION
Y1
B
S1
S2
C
MODEL 2S
THERMOSTAT SINGLE-STAGE
FURNACE TWO-SPEED
HEAT PUMP
See note 4, 6, 7, and 9
G
O/W2
W
R
YY2
L
Y1
O
W2
W3
A97130
→Fig. 12—Two-Speed Heat Pump
with 2-Stage or Variable-Speed Furnace
24 VAC HOT

24 VAC COMM

HEAT STAGE 3

COOL/HEAT
STAGE 2

FAN
R
C
G
W/W1
Y/Y2
R
C
RVS COOLING

COOL/HEAT
STAGE 1

RVS HEATING

OUTDOOR

SENSOR

CONNECTION
Y1
B
S1
S2
C
MODEL 2S
THERMOSTAT
TWO-STAGE OR
VARIABLE-SPEED
FURNACE TWO-SPEED
HEAT PUMP
See notes 1, 4, 5, 6, 7, and 9
G
O/W2
R
Y2
L
Y1
O
W2
W3
W2
O
Y1
W/W1
Y/Y2
*
*
A97131
→Fig. 13—Two-Speed Heat Pump
with Typical Fan Coil
24 VAC HOT

24 VAC COMM

HEAT STAGE 3

COOL/HEAT
STAGE 2

FAN
R
C
G
W/W1
Y/Y2
R
C
RVS COOLING

COOL/HEAT
STAGE 1

RVS HEATING

OUTDOOR

SENSOR

CONNECTION
Y1
B
S1
S2
W3
C
Y1
MODEL 2S
THERMOSTAT TYPICAL
FAN COIL TWO-SPEED
HEAT PUMP
See notes 4, 5, 6, 7, 9, and 10
Y/Y2
G
O/W2
*
W2
R
Y2
Y1
E
L
*
*
O
L
*W3
O
W2
6

R
Y/Y2
R
Y
W/W1 W1
C
MODEL AC
THERMOSTAT FK4C
EASY SELECT
TERMINAL BOARD SINGLE-SPEED
AIR CONDITIONER
J1 JUMPER
J2 JUMPER
See note 10
W2
Y/Y2
DH
G G
Y1
O
C
HEAT STAGE 1
24 VAC HOT
C
COOL STAGE 1
FAN
24 VAC COMM
A97240
→Fig. 14—Single-Speed Air Conditioner
with FK4C Fan Coil
24 VAC HOT

HEAT STAGE 1

24 VAC COMM

COOL STAGE 1

FAN
R
G
W/W1
Y/Y2
R
Y
CCC
MODEL HP
THERMOSTAT FK4C
EASY SELECT
TERMINAL BOARD SINGLE-SPEED
AIR CONDITIONER
J1 JUMPER
REMOVE
J2 JUMPER
FOR HEAT
STAGING
See notes 2, 3, and 10
G
W1
Y/Y2
DH
HEAT STAGE 2

N/A

N/A

OUTDOOR

SENSOR

CONNECTION
Y1
B
S1
S2
O/W2
Y1
O
W2
A97132
→Fig. 15—Single-Speed Air Conditioner
with FK4C Fan Coil
24 VOLT HOT

24 VOLT COMM

FAN

COOL STAGE 2

HEAT STAGE 1
R
Y/Y2
R
Y2
CCC
R
L
Y1
MODEL 2S
THERMOSTAT FK4C
EASY SELECT
TERMINAL BOARD TWO-SPEED
AIR CONDITIONER
J1 JUMPER
REMOVE
J2 JUMPER
FOR HEAT
STAGING
See notes 2, 3, 4, and 10
GG
Y/Y2
DH
W/W1 W1
HEAT STAGE 2

COOL STAGE 1
Y1
O/W2
Y1
O
W2
B
S1
S2
N/A

OUTDOOR

SENSOR

CONNECTION
A97133
→Fig. 16—Two-Speed Air Conditioner
with FK4C Fan Coil
24 VAC HOT

24 VAC COMM

FAN

COOL/HEAT
STAGE 1

HEAT STAGE 2
R
Y/Y2
R
CCC
R
MODEL HP
THERMOSTAT FK4C
EASY SELECT
TERMINAL BOARD SINGLE-SPEED
HEAT PUMP
J1 JUMPER
J2 JUMPER
See notes 6 and 10
GG
Y/Y2
DH
W/W1 W1
N/A

RVS COOLING

RVS HEATING

OUTDOOR

SENSOR

CONNECTION
Y1
B
S1
S2
O/W2
Y1
O
W2 W2
Y
O
A97134
→Fig. 17—Single-Speed Heat Pump
with FK4C Fan Coil
7

24 VAC HOT

24 VAC COMM

FAN

COOL/HEAT
STAGE 2

HEAT STAGE 3
R
Y/Y2
R
CCC
R
MODEL 2S
THERMOSTAT FK4C
EASY SELECT
TERMINAL BOARD TWO-SPEED
HEAT PUMP
J1 JUMPER
J2 JUMPER
See notes 4, 6, 7, 9 and 10
GG
Y/Y2
DH
W/W1 W1
W2W2
RVS COOLING

COOL/HEAT
STAGE 1

RVS HEATING

OUTDOOR

SENSOR

CONNECTION
Y1
L
S1
S2
B
Y1 Y1
Y2
O/W2 OO
A97135
→Fig. 18—Two-Speed Heat Pump
with FK4C Fan Coil
24 VAC HOT

24 VAC COMM

HEAT STAGE 1

COOL STAGE 1

FAN
C
R
G
W/W1
Y/Y2
MODEL AC
THERMOSTAT SPLICE
BOX
RED
BRN
WHT
YEL
GRN
See note 7
A96297
Fig. 19—Single-Speed Packaged Air Conditioner
with Single-Stage Gas Furnace (48SS, SX)
B
S1
S2
SPLICE
BOX
RED
YEL
WHT
See notes 2, 7, and 11
O/W2
HEAT STAGE 2
N/A
Y1
COOL STAGE 1
OUTDOOR

SENSOR

CONNECTION
HEATER
CONTROL BOX
GRN
BRN BRN
24 VAC HOT

24 VAC COMM

HEAT STAGE 1

COOL STAGE 2

FAN
C
R
G
W/W1
Y/Y2
MODEL 2S
THERMOSTAT
A97136
→Fig. 20—Single-Speed Packaged Air Conditioner
with Single-Stage Electric Heat (50SS, SX, ZP)
B
S1
S2
SPLICE
BOX
YEL
WHT
PNK
See notes 2, 7, 8, and 11
O/W2
HEAT STAGE 2
N/A
Y1
COOL STAGE 1

OUTDOOR

SENSOR

CONNECTION
HEATER
CONTROL BOX
GRN
VIO
BRN BRN
RED RED
24 VAC HOT

24 VAC COMM

HEAT STAGE 1

COOL STAGE 2

FAN
C
R
G
W/W1
Y/Y2
MODEL 2S
THERMOSTAT
RED(TRAN)
A97137
→Fig. 21—Single-Speed Packaged Air Conditioner
with 2-Stage Electric Heat (50SS, SX, ZP)
8

B
S1
S2
SPLICE
BOX
YEL
WHT
See notes 7 and 11
O/W2
HEAT STAGE 2
N/A
Y1
COOL/HEAT
STAGE 1

OUTDOOR

SENSOR

CONNECTION
HEATER
CONTROL BOX
GRN
ORN
BRN BRN
RED
24 VAC HOT

24 VAC COMM

HEAT STAGE 3

COOL/HEAT
STAGE 2

FAN
C
R
G
W/W1
Y/Y2
MODEL 2S
THERMOSTAT
A97138
→Fig. 22—Single-Speed Packaged Heat Pump
with Single-Stage Electric Heat (50HS, HX, ZH)
B
S1
S2
SPLICE
BOX
YEL
WHT
O/W2
HEAT STAGE 2
N/A
Y1
COOL/HEAT
STAGE 1

OUTDOOR

SENSOR

CONNECTION
HEATER
CONTROL BOX
ORN
VIO
BRN BRN
RED RED
24 VAC HOT

24 VAC COMM

HEAT STAGE 3

COOL/HEAT
STAGE 2

FAN
C
R
G
W/W1
Y/Y2
MODEL 2S
THERMOSTAT
PNK
RED(TRAN)
See notes 7, 8, and 11
A97139
→Fig. 23—Single-Speed Packaged Heat Pump
with 2-Stage Electric Heat (50HS, HX, ZH)
B
S1
S2
SPLICE
BOX
WHT
YEL
O/W2
HEAT STAGE 2
N/A
Y1
COOL/HEAT
STAGE 1

OUTDOOR

SENSOR

CONNECTION
GRN
ORN
BRN
RED
24 VAC HOT

24 VAC COMM

HEAT STAGE 3

COOL/HEAT
STAGE 2

FAN
C
R
G
W/W1
Y/Y2
MODEL 2S
THERMOSTAT
See notes 7 and 11
A97140
→Fig. 24—Single-Speed Packaged Heat Pump
with Single-Stage Gas Furnace (48HX)
→WIRING DIAGRAM NOTES:
1. Furnace must control second-stage heat.
2. Cut jumper R19 to convert thermostat to AC operation.
3. O/W2 can control second-stage heat. Refer to indoor equip-
ment Installation Instructions for proper setup.
4. Refer to outdoor unit Installation Instructions for latent kit
requirements.
5. Terminals marked with *may not be present on equipment.
6. O/W2 energizes reversing valve in cooling.
7. Refer to outdoor equipment Installation Instructions for proper
setup.
8. Omit red and pink wires from diagram when wiring a 50ZP,
ZH with 2-stage heaters.
9. Select the "ZONE" position on the 2-speed heat pump control
board.
10. Refer to fan coil Installation Instructions for proper wiring.
11. Program thermostat to bring on G (fan) with any W (heat)
selection. See Step 4, item 5 under thermostat configuration.
9

OPERATIONAL INFORMATION
Five-minute Compressor Timeguard
This timer prevents the compressor from starting unless it has been off for at least 5 minutes. It can be defeated for 1 cycle by simultaneously
pressing the FAN mode button and the INCREASE TEMPERATURE button.
Fifteen-minute Cycle Timer
This timer prevents the start of a heating or cooling cycle until at least 15 minutes after the last start of the same cycle. Its function is to assure
that equipment is not cycled more than 4 times per hr. This timer is defeated for 1 cycle when the desired temperature is manually changed.
It can also be defeated for 1 cycle by simultaneously pressing the FAN mode button and the INCREASE TEMPERATURE button.
Fifteen-minute Staging Timer
In multistage heating or cooling, this timer prevents any higher stage from turning on until the preceding stage has been on for 15 minutes.
This timer is defeated if the temperature error is greater than 5˚F (usually due to a large change in desired temperature).
Two-minute Minimum On Time
In normal operation, when a stage turns on, it will not turn off for a minimum of 2 minutes.
Heat/Cool Setpoints (Desired Temperatures)
A minimum difference of 3˚F is enforced between heating and cooling desired temperatures. This is done by allowing 1 setting to "push" the
other, to maintain this difference.
Auto Changeover
When the auto changeover mode is selected, a change from heat to cool (or vice versa) will not occur until an opposite mode demand has existed
for 20 minutes. If the desired temperature is changed, the 20 minute requirement is deleted.
Emergency Heat Mode
When thermostat is configured as a heat pump and emergency heat mode is selected, all Y signals are locked out and W becomes energized
upon a call for heat.
Power On Check
When AC power is first applied, all segments of the display are turned on for a few sec. Following this, the temperature display indicates the
model/configuration via the following 2 digit code:
AC—1-speed air conditioner, HP—1-speed heat pump, A2—2-speed air conditioner, H2—2-speed heat pump.
Error Codes
E1 — If the thermostat cannot properly read room temperature, the display will indicate E1 and all outputs (except the fan if on) will turn off.
This is to prevent operation of the equipment if the thermostat has failed.
E2 — If the AC line voltage drops below a minimum (brownout) level, all outputs are turned off and the display indicates E2. This condition
will remain for 15 sec after proper line voltage is restored. If the AC line voltage disappears completely, the display will immediately
go blank.
Energy Savings Icon
This icon is displayed under these conditions:
1-speed HP heating without auxiliary heat.
2-speed HP on LO or HI speed heating without auxiliary heat.
2-speed HP or AC on LO speed cooling. →Thermostat Troubleshooting
SYMPTOM WHAT TO CHECK
No LCD on temperature display Check for 24vac between R and C at terminal connections. Both R and C must be con-
nected for proper operation.
"E2" on temperature display Brownout condition or too low of voltage to thermostat. Double check wiring and check for
24vac between R and C. E2 will clear 15 sec after proper voltage is restored.
"E1" on temperature display Temperature sensor reading out of range. Check sensor for damage. If recycling power
does not clear display, thermostat should be replaced.
"Clean Filter" on temperature display After the selected number of hr of blower operation "clean filter" will display on LCD. This is to remind the homeowner to "check" filter. Press "reset filter" button to clear display and
reset timer to 0.
"--" on temperature display If the outdoor sensor is open, not connected, or shorted "--" will be displayed in place of
outdoor temperature.
Cooling will not come on
Select COOL mode. Set desired temperature to 10˚F below room temperature. Simulta-
neously press FAN and INCREASE TEMPERATURE buttons to defeat timers. Check for
24vac at Y (first-stage) terminal. If present, thermostat is OK and problem is with equip-
ment or wiring. If not present, replace thermostat.
Heating will not come on
Select HEAT mode. Set desired temperature to 10˚F above room temperature. Simulta-
neously press FAN and INCREASE TEMPERATURE buttons to defeat timers. Check for
24vac at Y (first-stage) terminal (with heat pump) or W/W1 (with air conditioner) terminal.
If present, thermostat is OK and problem is with equipment or wiring. If not present, re-
place thermostat.
10

SERVICE TRAINING
Packaged Service Training programs are an excellent way to increase your
knowledge of the equipment discussed in this manual, including:
 • Unit Familiarization • Maintenance
 • Installation Overview • Operating Sequence
A large selection of product, theory, and skills programs is available, using popular
video-based formats and materials. All include video and/or slides, plus companion
book.
Classroom Service Training plus "hands-on" the products in our labs can mean
increased confidence that really pays dividends in faster troubleshooting, fewer
callbacks. Course descriptions and schedules are in our catalog.
CALL FOR FREE CATALOG 1-800-962-9212
[ ] Packaged Service Training [ ] Classroom Service Training A94328
11

Copyright 1997 CARRIER Corp. • 7310 W. Morris St. • Indianapolis, IN 46231 tstat14si
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 4
Tab misc. misc. PC 101 Catalog No. 03TS-TA1 Printed in U.S.A. Form TSTAT-14SI Pg 12 5-97 Replaces: TSTAT-11SI