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