ICM Controls SC 4211 General instructions

2-Stage Heat Pump
Auto Changeover
Hardwire
SC 4211
Installation, Operation & Application Guide
For more information on our complete range of American-made
products – plus wiring diagrams, troubleshooting tips and more,
visit us at www.icmcontrols.com
• Configurable
• 2-Stage Heat Pump Systems
• Large Display With Backlight
• Selectable Fahrenheit or Celsius
• SimpleSet™ Field Programming
• Status Indicator Lights
• Relay Outputs
(minimum voltage drop in thermostat)
• Remote Sensor Compatible
• Ideally Suited for:
– Residential (New Construction/Replacement)
– Light Commercial
Non-Programmable Electronic Thermostat

Table of Contents
PartsDiagram ............................................................................1
IconDescriptions..........................................................................2
Specifications.............................................................................2
ImportantSafetyInformation ................................................................3
PackageContents/ToolsRequired.............................................................3
ToRemoveExistingThermostat..............................................................3
ToInstallThermostat.......................................................................4
WiringDiagrams...........................................................................5
SingleCompressorheatpumpwithelectricbackup ..............................................5
DualCompressorheatpumpwithelectricbackup................................................5
RemoteSensorInstallation(Optional)..........................................................6
Terminal Designator Descriptions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
SC4211 Output Chart. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
ConfigurationMode........................................................................8
ConfigurationModeSettings.................................................................9
ModeofOperation........................................................................14
ButtonFunctions.........................................................................15
OperatingModes.........................................................................16
LEDIndicators...........................................................................17
TestingtheThermostat....................................................................18
LockoutFeature..........................................................................19
SimpleSetTM FieldProgramming..............................................................20
Troubleshooting..........................................................................21

1
Parts Diagram
Configuration switch
Reset switch
Left (system)
button
Right (fan)
button
Down button
Up button
Field programming pins
RESET CONFIG
FP

2
Specications
Icon Descriptions
Fan operation icon
Cooling operation icon
Heating operation icon
Lock mode
activated
Room
temperature
offset activated
Electrical rating: • 24 VAC (18-30 VAC)
• 1 amp maximum per terminal
• 3 amp maximum total load
Temperature control range: 45°F to 90°F (7°C to 32°C) Accuracy: ± 1°F (± 0.5°C)
System configuration: 2-stage heat pump
Timing: Anti-short Cycle: 4 minutes (bypass anti-short cycle delay by returning to OFF
mode for 5 seconds)
Backlight Operation: 10 seconds
Terminations: S1, S2, L, R, C, O/B, Y1, W2, Y2, G, E
Emergency heat
indicator

3
Package Contents/Tools Required
Package includes: SC4211 thermostat on base, thermostat cover, wiring labels, screws and wall
anchors, Installation, Operation and Application Guide
Tools required for installation: Drill with 3/16” bit, hammer, screwdriver
Important Safety Information
WARNING! : Always turn off power at the main power supply before installing, cleaning, or
removing thermostat.
• This thermostat is for 24 VAC applications only; do not use on voltages over 30 VAC
• All wiring must conform to local and national electrical and building codes
• Do not use air conditioning when the outdoor temperature is below 50 degrees; this can damage your
A/C system and cause personal injuries
• Use this thermostat only as described in this manual
To Remove Existing Thermostat
ELECTRICAL SHOCK HAZARD – Turn off power at the main service panel by removing the fuse
or switching the appropriate circuit breaker to the OFF position before removing the existing
thermostat.
1. Turn off power to the heating and cooling system by removing the fuse or switching the appropriate
circuit breaker off.
2. Remove cover of old thermostat. This should expose the wires.
3. Label the existing wires with the enclosed wire labels before removing wires.
4. After labeling wires, remove wires from wire terminals.
5. Remove existing thermostat base from wall.
6. Refer to the following section for instructions on how to install this thermostat.

4
To Install Thermostat
ELECTRICAL SHOCK HAZARD – Turn off power at the main service panel by removing the fuse
or switching the appropriate circuit breaker to the OFF position before removing the existing
thermostat.
IMPORTANT: Thermostat installation must conform to local and national building and electrical
codes and ordinances.
Note: Mount the thermostat about five feet above the floor. Do not mount the thermostat on an
outside wall, in direct sunlight, behind a door, or in an area affected by a vent or duct.
1. Turn off power to the heating and cooling system by removing the fuse or switching the
appropriate circuit breaker off.
2. To remove cover, pull gently at the seam at the top.
3. Put thermostat base against the wall where you plan to mount it (Be sure wires will feed through
the wire opening in the base of the thermostat).
4. Mark the placement of the mounting holes.
5. Set thermostat base and cover away from working area.
6. Using a 3/16” drill bit, drill holes in the places you have marked for mounting.
7. Use a hammer to tap supplied anchors in mounting holes.
8. Align thermostat base with mounting holes and feed the control wires through slit in thermal
intrusion barrier and into wire opening.
9. Use supplied screws to mount thermostat base to wall.
10. Insert stripped, labeled wires in matching wire terminals.
CAUTION!: Be sure exposed portion of wires does not touch other wires.
11. Gently tug wire to be sure of proper connection. Double check that each wire is connected to the
proper terminal.
12. Turn on power to the system at the main service panel.
13. Configure thermostat (see Page 8) to match the type of system you have.
14. Replace cover on thermostat by snapping it in place.
15. Test thermostat operation as described in “Testing the Thermostat” (Page 18).

5
Single Compressor
heat pump with electric backup
Dual Compressor
heat pump with electric backup
* outdoor sensor only reads outdoor temperature
Transformer
120
VAC 24 VAC
Reversing Valve
Compressor
Auxiliary Heat
Optional
remote or
outdoor sensor
Service Led Wire
Emergency Heat
Fan
Compressor #2
Transformer
120
VAC 24 VAC
Reversing Valve
Compressor #1
Auxiliary Heat
Optional
remote or
outdoor sensor
Service Led Wire
Emergency Heat
Fan
Wiring Diagrams
Note: For systems without emergency strip heat, a jumper wire should be placed between W2 & E.

6
Remote Sensor Installation (Optional)
1. Remove cover from remote sensor housing.
2. Select an appropriate location for mounting the remote sensor.
3. Mount remote sensor unit using hardware provided.
4. Install two strand shielded wire between remote sensor and thermostat. Shielded wire must be
used. Do not run remote sensor wire in conduit with other wires.
• Wire 1 should run between the S1 terminal on the thermostat and the S1 terminal on
the remote sensor
• Wire 2 should run between the S2 terminal on the thermostat and the S2 terminal on
the remote sensor
• Connect the shielding of the wire to the S2 terminal on the thermostat
5. Configure the thermostat to operate with the remote indoor sensor (see Configuration Mode setting
13, Page 12) or use it for an outdoor sensor.
Note:
Remote or outdoor
sensor reading can
be displayed by
simultaneously pressing
the Down and SYS
buttons.
Remote Sensor: (Shown: Optional ICM ACC-RT103 Remote Indoor Sensor;
for outdoor sensor, order ACC-OD103.)
(Shown: Optional ICM ACC-RT103 Remote Indoor Sensor; for outdoor sensor, order ACC-OD103.)

7
Terminal Designator Descriptions
1ST Cool 2ND Cool 1ST Heat 2ND Heat
Heat Pump (One Compressor) Y1, G, O Y1, G, O Y1, G, B Y1, W2, G, B
Heat Pump (Two Compressors) Y1, G, O Y1, Y2, G, O Y1, G, B Y1, Y2, G, B
Emergency Heat N/A N/A E, G E, W2, G
SC4211 Output Chart
L – Service Led indicator
R – 24 VAC hot
C – 24 VAC common
O/B – Configurable
O – cool active reversing valve
B – heat active reversing valve
Y1 – 1st stage cool, 1st stage heat
W2 – 2nd stage heat for single compressor systems, 2nd stage for Emergency heat
Y2 – 2nd stage cool for 2 compressor systems, 2nd stage heat for 2 compressor systems
G – Fan
E – 1st stage heat for Emergency heat mode
The SC4211 thermostat is configurable for most heat pump systems. The configuration directly affects
the outputs.
Use the output chart to correctly configure and wire the thermostat to your system.

8
Conguration Mode
OFF
1. Verify the SC4211 is in the OFF mode.
Press the SYS (left) button until off mode displays.
2. Remove the cover of the thermostat by gently pulling near one of the
corners at the top of the thermostat.
3. Press the CONFIG button for 1 second while the SC4211 is in OFF mode.
To exit configuration mode, press the CONFIG switch for 1 second.
Press the up or down button to change settings within each screen.
Down
button
Up
button
Press the right button to advance to the next screen.
Note: Pressing the left button will return you to the previous screen. Left
button
Right
button
The configuration mode is used to set the SC4211 to match your heat pump system.
To configure the SC4211, perform the following steps:
CONFIG
S1 S2 R C W
O/B GY1 W2 W3Y2
RESET CONFIG
FP

9
Conguration Mode Settings
The setup screens for Configuration Mode are as follows:
1. Temperature Scale (F or C)
Choose Fahrenheit or Celsius.
Press the up or down button to select.
Press the right button to advance to the next screen.
2. 1st Stage Temperature Differential (1°F to 5°F) (0.5°C to 2.5°C)
Set the number of degrees between your “setpoint” temperature and your
“turn on” temperature.
Press the up or down button to set differential value.
Press the right button to advance to the next screen.
3. 2nd Stage Temperature Differential (1°F to 5°F) (0.5°C to 2.5°C)
Set the number of degrees between when stage 1 turns on and when
stage 2 turns on.
Press the up or down button to set differential value.
Press the right button to advance to the next screen.
4. Staged Off Outputs
Select whether the outputs for heating and cooling are staged off
independently or are satisfied simultaneously.
1 = outputs staged off independently
0 = outputs off simultaneously
Press the up or down button to set.
Press the right button to advance to the next screen.

10
5. Minimum Deadband (1°F to 9°F) (1°C to 5°C)
Set the minimum separation between heat setpoint and cool setpoint in
Auto Changeover Mode.
Press the up or down button to set deadband value.
Press the right button to advance to the next screen.
Press the up or down button to select.
Press the right button to advance to the next screen.
6. System – Set for reversing valve operation and number of compressors in your system.
Choose System
Reversing Valve
Active
Number of Compressors
or Compressor Stages
Heat Pump
HP O 1
HP b 1
HP O 2
HP b 2

11
7. Auxiliary Delay ON – (0-30 minutes)
Set the delay time in minutes for auxiliary heat to be locked out after a
call for second stage.
Press the up or down button to select.
Press the right button to advance to the next screen.
8. Lockout (0-8°, COOL-HEAT)
Select the number of degrees set temperature can be changed during keypad
lockout. COOL-HEAT lockout allows adjustment of the set temperatures to
the maximum heat set temperature selected in Step 9 and minimum cool set
temperature selected in Step 10.
Note: The mode cannot be changed when the thermostat is locked.
Press the up or down button to select.
Press the right button to advance to the next screen.
9. Maximum Heat Setpoint (45°F to 90°F) (7°C to 32°C)
Adjust to control the maximum heat set temperature allowed.
Press the up or down button to select.
Press the right button to advance to the next screen.
10. Minimum Cool Setpoint (45°F to 90°F) (7°C to 32°C)
Adjust to control the minimum cool set temperature allowed.
Press the up or down button to select.
Press the right button to advance to the next screen.

12
12. Maximum Cycles Allowed Per Hour (- -, 2-6)
- - = as many as needed, 2-6 = maximum cycles/hour
Press the up or down button to select.
Press the right button to advance to the next screen.
11. Room Temperature Offset (+9°F to -9°F) (+4.5°C to -4.5°C)
Adjust to calibrate displayed room temperature to match actual room
temperature.
Note: When not set to 0, will display
Press the up or down button to select.
Press the right button to advance to the next screen.
13. Temperature Sensor (1-3)
1. Only on-board sensor determines room temperature.
2. Only remote sensor determines room temperature.
3. Average temperature of on-board and remote sensor.
Note: If there is no remote sensor, option 1 must be selected.
Press the up or down button to select.
Press the right button to advance to the next screen.

13
OFF
14. Cooling Fan Delay Off Time (0, 30, 60, 90 seconds)
Select the fan purge time for cooling.
Press the up or down button to select.
Press the right button to advance to the next screen.
Press CONFIG button for 2 seconds to exit configuration.

14
Mode of Operation
The SC4211 is a non-programmable, manual or auto changeover, 2-stage heat pump thermostat. An
outdoor sensor can be used to monitor the outdoor temperature.
The thermostat activates the heating appliance when the room temperature is below the set heat
temperature (by the differential temperature) and the red AUX indicator light (during electric strip heat
operation) on the thermostat will light. The SC4211 will stop outputting and the red light will turn off
when the call for heat has been satisfied. The thermostat will not let the compressor come on for 4
minutes after it turns off. This protects your compressor.
When the room temperature is greater than the set cool temperature (by the differential temperature),
the cooling device is activated. The SC4211 will stop outputting when the call for cooling is satisfied.
The thermostat will not let the compressor come on for 4 minutes after it turns off. This protects your
compressor.
The SC4211 has five possible operating modes: OFF, Heat, Emergency Mode, Cool, and Cool & Heat
mode. In off mode, the thermostat will not turn on heating or cooling devices. The manual fan can
be turned on in all operating modes using the fan button. In heat mode, the thermostat controls the
heating system. In the emergency mode, the compressor is locked out and the electric strip heat is
used to satisfy the heat call. In the cool mode, the thermostat controls the cooling system. In heat &
cool mode, the thermostat controls both the heating and cooling systems. The clock display alternates
with the set temperature display for heat & cool mode.
The SC4211 also has a button lockout feature. This enables the thermostat to be set to the proper
mode and temperature and locked so it cannot be tampered with.

15
Button Functions
UP
Used to increase the time, set temperatures and to adjust configuration settings.
DOWN
Used to decrease the time, set temperatures and to adjust configuration settings.
SYS (left)
Used to change from OFF, HEAT, EMER HEAT, COOL and COOL & HEAT modes
FAN (right)
Used to turn on and off the indoor fan.
UP, SYS and Fan
Held in simultaneously for 10 seconds to lock and unlock the thermostat.
DOWN and SYS
Pressed simultaneously to display outdoor temperature if outdoor remote sensor is connected.
SYStem (left) FAN (right)
Down button
Up button

16
Operating Modes
There are five possible operating modes for the SC4211. Off, Heat, Emergency Heat, and Cool & Heat
modes are accessed by pressing the SYS (left) button.
OFF Mode
• In this mode, the thermostat will not turn on the heating or cooling
devices
Note: The indoor fan can be turned on manually in every operating
mode by pressing the FAN (right) button. The word FAN
shows on the display and the fan icon appears when the
fan operates. OFF
Heat Mode
• In this mode, the thermostat controls the heating system. When the
heat outputs, the flame icon apprears on the display.
Note: There is a four minute delay for your compressor to restart
after it has turned off. To bypass the compressor time delay,
go to OFF mode for 5 seconds.
Emergency Heat Mode
• In emergency heat mode, the heat pump system will be disabled and
auxiliary heat will become the primary source of heat.
Note: The red EMER will be lit when operating in Emergency heat
mode.

17
Cool Mode
• In this mode, the thermostat controls the cooling system. When the
cooling outputs, the snowflake icon apprears on the display.
Note: There is a four minute delay for your compressor to restart
after it has turned off. To bypass the compressor time delay,
go to OFF mode for 5 seconds.
Cool and Heat Mode (Auto Changeover)
• In this mode, the thermostat controls the cooling and heating systems,
automatically changing over from one to the other as needed.
• The timing display alternates with the set temperature every 10
seconds in the cool and heat mode.
LED Indicators
AUX (GREEN)
CHECK (RED)
EMER (RED)
There are three LED indicators located on the front of the
thermostat. They are designed to inform you of the following:
AUX (GREEN): This turns on when the auxiliary (back-up)
heating is in operation. This is the second
(non-economy) stage of heat.
CHECK (RED): When this turns on, a malfunction has
occurred somewhere in the heat pump
system. Please contact a qualified service
technician as soon as possible to check your
system.
EMER (RED): This light turns on whenever the emergency
heat is selected. While in the emergency heat
mode, the heat pump compressor is off,
and the emergency heat (and auxiliary heat)
maintains the setpoint temperature.

18
Heat Test
1. Press SYS (left) button until heat mode is displayed.
2. Adjust the set temperature so it is 5 degrees above the room temperature.
3. Heat should come on within a few seconds. Red Aux LED may turn on.
4. Adjust the set temperature 2 degrees below the room temperature and the
heat should turn off. There may be a fan delay on your system.
Note: There is a four-minute delay to protect your compressor after it
turns off. To bypass the compressor time delay, go to OFF mode for 5 seconds.
Testing the Thermostat
Once the thermostat is configured, it should be thoroughly tested.
CAUTION! : Do not energize the air conditioning system when the outdoor temperature is
below 50 degrees. It can result in equipment damage or personal injury.
Cool Test
1. Press SYS (left) button until cool mode is displayed.
2. Adjust set temperature so it is 5 degrees below room temperature.
3. A/C should come on within a few seconds.
4. Adjust the set temperature 2 degrees above the room temperature and the
A/C should turn off. There may be a fan delay on your system.
Note: There is a four-minute time delay to protect the compressor after it
turns off. To bypass the compressor time delay, go to OFF mode for 5 seconds.
Fan Test
1. Press FAN (right) button. Fan displays. Indoor fan turns ON.
2. Press FAN (right) button. Indoor fan turns OFF.
OFF