Honeywell Prestige 2.0 THX9421 User manual

PRODUCT DATA
68-0311-07
THX9321 Prestige®2.0 and
THX9421 Prestige®IAQ with EIM
APPLICATION
The Prestige 2.0 and Prestige IAQ Systems feature an
effortless, 7-Day programmable color touchscreen
thermostat that provides control of temperature,
humidification, dehumidification, and ventilation for up to
4 Heat/2 Cool heat pump systems or up to 3 Heat/2 Cool
conventional systems for residential and commercial
applications.
FEATURES
• RedLINK™ Compatible
Increase your content and profit per job by including
RedLINK™ accessories that meet your customers
comfort and convenience needs. RedLINK accessories
include the Wireless Outdoor Sensor, Portable Comfort
Control (PCC), Equipment Interface Module (EIM),
RedLINK Internet Gateway, Wireless Indoor Sensor, Tru-
eSTEAM™ humidifier with Wireless Adapter,
TrueZONE™ zoning panel with Wireless Adapter, Vent
Boost Remote and Entry/Exit Remote.
• Also Compatible with Equipment Remote Module
(ERM) ERM5220R
• Customizable Service Reminders
Set up to 10 service reminders. Choose from the pre-set
options or customize your own. Reminders based on
date or the outdoor temperature.
• Delta T Alerts and Diagnostics
Alerts give customers a sense of security while allowing
you to service or replace the equipment prior to a loss of
heating or cooling. Based on limits you set at installa-
tion, customers can be alerted when their system is not
operating as expected. The system alert will instruct
customers to contact you for assistance. Requires
Equipment Interface Module.
• Delta T Installer Test
Save time by viewing Delta T while running a system
test to verify proper operation. Requires Equipment
Interface Module.
• Universal Inputs
EIM - S1, S2, S3, S4
Assignable inputs allow you to setup Indoor and
Outdoor Temperature Sensors, Discharge and Return
Air Sensors or Dry Contact Devices. Dry Contact
Devices can be used to trip pre-set or customized alerts
on the thermostat home screen. Requires Equipment
Interface Module.
• Data Logs
The thermostat stores an Alerts Log, User Interactions
Log and a Performance Log to quickly determine if an
issue is caused by a system error or an accidental user
error. Note: The Performance Log only applies to the
THX9421 thermostat.
• Selectable for Residential and Light Commercial
Applications
One thermostat does it all to meet the needs of Resi-
dential and Light Commercial applications. Simply
select Residential or Commercial during the installer
setup. If Commercial is selected, the thermostat will use
commercial language, meet building codes and offer
365 day holiday scheduling.
• USB Port for Quick Installer Setup
Save time by using a USB stick to upload installer set-
tings, and service reminders in one simple step.
• Selectable Sensors
When paired with a Wireless Indoor Sensor(s) you have
the ability to choose which sensor(s) to use for tem-
perature, humidification and dehumidification. They
can be used in combination for temperature averag-
ing—or individually—to condition humidity levels in
separate spaces.
THX9321 Prestige®2.0
THX9421 Prestige®IAQ with EIM

THX9321 PRESTIGE®2.0 AND THX9421 PRESTIGE®IAQ WITH EIM
68-0311—07 2
ORDERING INFORMATION
When purchasing replacement and modernization products from your TRADELINE® wholesaler or distributor, refer to the
TRADELINE® Catalog or price sheets for complete ordering number. If you have additional questions, need further
information, or would like to comment on our products or services, please write or phone:
1. Your local Honeywell Environmental and Combustion Controls Sales Office (check white pages of your phone
directory).
2. Honeywell Customer Care
1985 Douglas Drive North
Golden Valley, Minnesota 55422-4386
3. http://customer.honeywell.com or http://customer.honeywell.ca
International Sales and Service Offices in all principal cities of the world. Manufacturing in Belgium, Canada, China,
Czech Republic, Germany, Hungary, Italy, Mexico, Netherlands, United Kingdom, and United States.
CONTENTS
Application ..................................................... 1
Specifications ................................................ 3
Ordering Information ..................................
Ordering Info
System Installation ...................................... 8
When Installing this Product... .............................. 8
Installing Equipment
Interface Module (if used) ........................................... 10
Wiring 24 Vac Common ............................................ 10
Selecting Discharge and Return Air Temperature Sen-
sor Mounting Locations ........................................... 10
Selecting Discharge and Return Air Temperature Sen-
sor Mounting Locations ............................................ 10
Selecting Return Air Temperature Sensor Mounting
Location ........................................................................... 11
Selecting Thermostat Location ............................. 12
Installing Wallplate ................................................... 12
Power Optional REDLINK™ Accessories ............. 14
Linking Thermostat to Equipment Interface Module
(if used) ......................................................................... 15
Linking RedLINK™ Accessories ............................. 16
Installer Tests ................................................ 66
Using the Equipment Test ....................................... 67
Using the Wireless Signal Strength Test ............. 67
Mounting Optional Accessories ............................ 68
Alerts and Diagnostics ................................ 86
Delta T Diagnostics ................................................... 86
Before You Set Up Delta T Diagnostics ................ 86
Setting up Alerts and Diagnostics ........................ 87
Delta T Alerts .............................................................. 89
Delta T Alerts and Utility Saver Switches ............ 90
Data Logs ..................................................................... 90
Alerts Log ......................................................................... 91
User Interactions Log ................................................. 92
Dry Contact Alerts ..................................................... 94
Heat Pump and Backup Heat Operation 100
Indoor Air Quality (IAQ) Control ............... 102
Humidification ........................................................... 102
Set up Humidification ................................................. 103
Control Humidification Level .................................. 104
Dehumidification - Residential ............................. 105
Set up Dehumidification With Cooling System 106
Set up Dehumidification
With Whole House Dehumidifier ............................ 107
Set up Dehumidification Away Mode .................... 109
Control Dehumidification Level .............................. 109
Dehumidification - Commercial ............................ 110
Set up Dehumidification With Cooling System 111
Set up Dehumidification With Dehumidifier ...... 112
Control Dehumidification Level .............................. 113
Ventilation ................................................................... 114
Set up Ventilation ......................................................... 115
IAQ Reminders .............................................. 118
Customizable Reminders .......................... 119
USB Port ......................................................... 121
Portable Comfort Control .......................... 131
Remote Indoor Sensors .............................. 132
Commercial Features .................................. 123
Ramp Rates ................................................................. 126
Custom Names ........................................................... 126
Remote Setback ......................................................... 126
Economizer and
Time of Day (TOD) Operation ..................................... 128
Pre-Occupancy Purge .............................................. 128
Staging Control .......................................................... 97
Optional Accessories .................................. 130
Troubleshooting ........................................... 163
Wiring .............................................................. 138
EIM Wiring Diagrams ............................................... 141
Geothermal Radiant Heat ....................................... 100
THX9321 Thermostat Wiring Diagrams .............. 144
THX9321 Thermostat Wiring Diagrams Using Univer-
sal Relays to Control Heating or Cooling ............ 145
Wiring IAQ Equipment or a Heat/Cool Stage to the
Universal Terminals .................................................. 152
Economizer Module Wiring Diagrams ................. 154
Wiring C7089U1006 Outdoor Sensor .................. 157
Wiring guide — Wired Indoor Sensors .................. 158
Regulatory Information ............................. 163

THX9321 PRESTIGE®2.0 AND THX9421 PRESTIGE®IAQ WITH EIM
368-0311—07
SPECIFICATIONS
Thermostat Description:
Electrical Ratings for:
Equipment Interface Module and the THX9321 Prestige
2.0 Thermostat
NOTE: To find what terminals are available on the Equip-
ment Interface Module and the Prestige Thermo-
stats, see “Terminal Designations” below the
table.
Terminal Designations:
— Equipment Interface Module: R, RC, RH, C, W-O/B,
W2-AUX 1, W3-AUX 2, Y, Y2, G, A-L/A, U1 U1, U2
U2, U3 U3, S1 S1, S2 S2, S3 S3, S4 S4, A, B, C, D
— THX9421 Thermostat: R, C
— THX9321 Thermostat: R, RC, C, W-O/B, W2-AUX/E,
Y, Y2, G, A-L/A, K, U1 U1, U2 U2
Power Consumption of THX9421/THX9321:
Full brightness = 3.0 VA
1/2 brightness = 2.1 VA
Backlight off = 1.9 VA
RedLINK Communication:
Frequency: 900 Mhz frequency range
Re-Sync Time: RedLINK devices re-establish communica-
tion within 6 minutes after AC power resumes.
Temperature Setting Range:
Heating: 40 to 90 °F (4.5 to 32 °C).
Cooling: 50 to 99 °F (10 to 37 °C).
Temperature Sensor Accuracy: ± 1.5 °F at 70 °F (0.75 °C
at 21.0 °C)
Humidification Setting Range:
10% to 60% RH.
Dehumidification Setting Range:
40% to 80% RH.
Humidity Display Range:
0% to 99%.
Humidity Sensor Accuracy: ± 5% RH from 30% to 50%
RH at 75 °F (24 °C).
Cool Indication:
Prestige 2.0 and Prestige IAQ displays “Cool On” when the
thermostat turns the cooling on.
Heat Indication:
Prestige 2.0 and Prestige IAQ displays “Heat On” when the
thermostat turns the heating on.
Auxiliary Heat Indication:
Prestige 2.0 and Prestige IAQ displays “Auxiliary Heat On”
when the thermostat turns the auxiliary heat on.
Interstage Differential:
Comfort: The thermostat keeps the indoor temperature
within 1 degree of the setpoint (droop less control). The
thermostat turns on stage 2 when the capacity on stage
1 reaches 90%.
When the interstage differential is set to 1.0 or higher, the
thermostat stages the equipment based on how far the
indoor temperature is from the setpoint (ISU 3030 to
3090). See page 31 for more information.
Clock Accuracy: ± 1 minute per month at 77 °F (25 °C). ±
2 minutes per month over the operating ambient tem-
perature range.
Mounting Means:
Thermostat mounts directly on the wall in the living space
using mounting screws and anchors provided. Fits a
horizontal 2 x 4 in. junction box.
Equipment Interface Module (EIM) mounts on HVAC
equipment or on a wall in the equipment room.
Feature Description
Powering method •Common wire only
System types (up
to 4 heat/2 cool
heat pump and up
to 3 heat/2 cool
conventional)
•Gas, oil or electric heat with air
conditioning
•Warm air, hot water, high-
efficiency furnaces, heat pumps,
steam and gravity
•Cool only
Changeover Manual or Auto changeover
selectable
System setting Em Heat-Heat-Off-Cool-Auto
Fan setting Auto-On-Circ-Follow Schedule
Terminal
Voltage
(50/60 Hz)
Max. Current
Rating
W - O/B 18 to 30 VAC 1.00A
Y (cooling) 18 to 30 VAC 1.00A
G (fan) 18 to 30 VAC 0.50A
W2 - Aux 1 (heating) 18 to 30 VAC 0.60A
W3 - Aux 2 (heating) 18 to 30 VAC 0.60A
Y2 (cooling) 18 to 30 VAC 0.60A
A-L/A (Output) 18 to 30 VAC 1.00A
U1, U1
U2, U2
U3, U3
18 to 30 VAC 0.50A

THX9321 PRESTIGE®2.0 AND THX9421 PRESTIGE®IAQ WITH EIM
68-0311—07 4
Fig. 1. Dimensions of THX9421 Prestige IAQ thermostat
in in. (mm).
Fig. 2. Dimensions of THX9421 Prestige IAQ cover
plates in in. (mm).
Fig. 3. Dimensions of THX9321 Prestige®2.0 thermostat
in in. (mm).
Fig. 4. Dimensions of THX9321 Prestige 2.0 cover plate
in in. (mm).
Fig. 5. Dimensions of Equipment Interface Module in in.
(mm).
M34630
3-5/16 (84)
3-1/2
(89)
4-1/2 (115) 7/8
(22)
M34262
1-25/32
(46)
5-33/64
(140)
2-1/8
(54)
4-21/64
(110)
1-25/32
(46)
6-7/8
(175)
2-1/8
(54)
5
(127)
M33329A
6-13/16 (173)
3-5/16 (84) 1-7/16
(36)
3-7/8
(99)
M33330
3-19/64 (84)
7-29/32 (201)
5-1/2
(140)
M33331
4-53/64 (123)
8-7/8
(225)
9-11/32
(237)
1-19/32
(41)

THX9321 PRESTIGE®2.0 AND THX9421 PRESTIGE®IAQ WITH EIM
568-0311—07
Table 1. Prestige Kits.
Kit
Part Number
Included in Kit
Part Number Description
Prestige IAQ Kit
YTHX9421R5101WW
THX9421R5021WW Thermostat - White Front, White Side
THM5421R1021 Equipment Interface Module
C7089R1013 Wireless Outdoor Sensor
50062329-001 Discharge/Return Sensors (Qty. 2)
Prestige IAQ Kit
YTHX9421R5085WW
THX9421R5021WW Thermostat - White Front, White Side
THM5421R1021 Equipment Interface Module
50062329-001 Discharge/Return Sensors (Qty. 2)
Prestige IAQ Kit
YTHX9421R7001WW
THX9421R5021WW Thermostat - White Front, White Side
THM5421R1021 Equipment Interface Module
50062329-001 Discharge/Return Sensors (Qty. 2)
THM6000R7001 RedLINK Internet Gateway
Table 2. Thermostat Replacement Parts and Accessories.
Product Part Number
Operating
Ambient
Temperature
Operating Relative
Humidity
Shipping
Temperature
Physical Dimensions in in.
(mm) Color(s)
Thermostat THX9421R5021WW 32 to 120 °F
(0 to 48.9 °C)
5% to 90%
Non-Condensing
-20 to 120 °F
(-28.9 to 48.9 °C)
4-1/2 x 3-1/2 x 7/8
(115 x 88 x 22)
Front-
White,
Side-White
THX9421R5021BB
OBSOLETE
32 to 120 °F
(0 to 48.9 °C)
5% to 90%
Non-Condensing
-20 to 120 °F
(-28.9 to 48.9 °C)
4-1/2 x 3-1/2 x 7/8
(115 x 88 x 22)
Front-
Black,
Side-Black
THX9421R5021SG
OBSOLETE
32 to 120 °F
(0 to 48.9 °C)
5% to 90%
Non-Condensing
-20 to 120 °F
(-28.9 to 48.9 °C)
4-1/2 x 3-1/2 x 7/8
(115 x 88 x 22)
Front-
Silver, Side-
Gray
THX9421R5021WG
OBSOLETE
32 to 120 °F
(0 to 48.9 °C)
5% to 90%
Non-Condensing
-20 to 120 °F
(-28.9 to 48.9 °C)
4-1/2 x 3-1/2 x 7/8
(115 x 88 x 22)
Front-
White,
Side-Gray
THX9321R5030
OBSOLETE
32 to 120 °F
(0 to 48.9 °C)
5% to 90%
Non-Condensing
-20 to 120 °F
(-28.9 to 48.9 °C)
6-13/16 x 3-7/8 x 1-7/16
(173 x 99 x 36)
Arctic
White
Equipment
Interface Module
YTHM5421R1010*
THM5421R1021
-40 to 165 °F
(-40 to 73.9 °C)
5% to 95%
Non-Condensing
-20 to 165 °F
(-28.9 to 73.9 °C)
9-11/32 x 4-53/64 x 1-
19/32
(237 x 123 x 41)
Gray
Equipment remote
module
ERM5220R1018 Compressor:
-40 to 155 °F
(-40 to 68 °C)
Boiler:
30 to 130 °F
(-1 to 54 °C)
0% to 99%
Non-Condensing
-20 to 165 °F
(-28.9 to 73.9 °C)
6-39/64 x 6-7/8 x 1-
31/64"
(168 x 175 x 38)
Gray
Wireless Adapter
(For TrueZONE,
TrueSTEAM or
extend wireless
range of EIM)
THM4000R1000 -40 to 165 °F
(-40 to 73.9 °C)
5% to 95%
Non-Condensing
-20 to 165 °F
(-28.9 to 73.9 °C)
5-9/16 x 4-3/8 x 1-1/4
(141 x 112 x 32)
Gray
RedLINK Internet
Gateway
THM6000R1002
OBSOLETE
32 to 120 °F
(0 to 48.9 °C)
5% to 95%
Non-Condensing
-20 to 120 °F
(-28.9 to 48.9 °C)
6 x 4-7/8 x 2-1/2
(152 x 124 x 64)
Black
RedLINK Internet
Gateway
THM6000R7001 32 to 120 °F
(0 to 48.9 °C)
5% to 95%
Non-Condensing
-20 to 120 °F
(-28.9 to 48.9 °C)
3-7/8 x 3-9/16 x 1-1/8
(99 x 91 x 29 mm)
White
Portable Comfort
Control
REM5000R1001 32 to 120 °F
(0 to 48.9 °C)
5% to 90%
Non-Condensing
-20 to 120 °F
(-28.9 to 48.9 °C)
6-1/4 x 3-1/8 x 1-5/8
(158 x 80 x 38)
Front-
White,
Side-Gray
Wireless
Entry/Exit Remote
REM1000R1003 32 to 120 °F
(0 to 48.9 °C)
5% to 90%
Non-Condensing
-20 to 120 °F
(-28.9 to 48.9 °C)
3-15/16 x 1-15/16 x 5/8
(101 x 50 x 16)
Arctic
White
Wireless Vent and
Filter Boost
Remote
HVC20A1000 32 to 120 °F
(0 to 48.9 °C)
5% to 90%
Non-Condensing
-20 to 120 °F
(-28.9 to 48.9 °C)
3-15/16 x 1-15/16 x 5/8
(101 x 50 x 16)
Arctic
White
Wireless Outdoor
Sensor
C7089R1013 -40 to 140 °F
(-40 to 60 °C)
0% to 100%
Condensing
-40 to 120 °F
(-40 to 48.9 °C)
5 x 3-1/2 x 1-11/16
(127 x 89 x 43)
Gray

THX9321 PRESTIGE®2.0 AND THX9421 PRESTIGE®IAQ WITH EIM
68-0311—07 6
Wireless Indoor
Sensor
C7189R1004 0 to 120 °F
(-17.8 to 48.9
°C)
For optimal
Battery Life:
35 to 114 °F
(1.7 to 45.6 °C)
5% to 90%
Non-Condensing
-20 to 120 °F
(-28.9 to 48.9 °C)
2-7/8 x 1-7/8 x 15/16
(74 x 48 x 24)
Arctic
White
Wired Outdoor
Sensor
(10K ohm
Negative
Temperature
Coefficient)
C7089U1006 -40 to 120 °F
(-40 to 48.9 °C)
5% to 95%
Non-Condensing
-40 to 130 °F
(-40 to 54.4 °C)
1-1/2 (38) - -
Wired Wall Mount
Indoor Sensor
(10K ohm
Negative
Temperature
Coefficient)
C7189U1005 45 to 88 °F
(7 to 32 °C)
5% to 95%
Non-Condensing
-20 to 120 °F
(-28.9 to 48.9 °C)
2-9/32 x 1-1/2 x 11/16
(58 x 38 x 18)
Premier
White
Wired Wall Mount
Indoor Sensor
(20K ohm
Negative
Temperature
Coefficient)
TR21 45 to 99 °F
(7 to 37 °C)
5% to 95%
Non-Condensing
-40 to 150 °F
(-40 to 65.5 °C)
4-9/16 x 3 x 7/8
(116 x 76.5 x 22)
White
Wired Wall Mount
Indoor Sensor
(10K ohm
Negative
Temperature
Coefficient)
TR21-A 45 to 99 °F
(7 to 37 °C)
5% to 95%
Non-Condensing
-40 to 150 °F
(-40 to 65.5 °C)
4-9/16 x 3 x 7/8
(116 x 76.5 x 22)
White
Wired Flush Mount
Indoor Sensor
(20K ohm
Negative
Temperature
Coefficient)
C7772A1004 45 to 99 °F
(7 to 37 °C)
5% to 95%
Non-Condensing
-40 to 150 °F
(-40 to 65.5 °C)
4-1/2 x 2-3/4 x 5/16
(114 x 70 x 8)
Brushed
Stainless
Steel
Wired Flush Mount
Indoor Sensor
(20K ohm
Negative
Temperature
Coefficient)
C7772A1012 45 to 99 °F
(7 to 37 °C)
5% to 95%
Non-Condensing
-40 to 150 °F
(-40 to 65.5 °C)
4-1/2 x 2-3/4 x 5/16
(114 x 70 x 8)
Brushed
Stainless
Steel
Discharge or
Return Air Sensor
(10K ohm
Negative
Temperature
Coefficient)
C7735A1000* 0 to 200 °F
(- 17.8 to 93.3
°C)
- - -20 to 120 °F
(-28.9 to 48.9 °C)
Probe:
3-3/4 x 1/4 (77 x 6.4)
Cap Diameter:
2-7/16 (62)
Gray
Discharge or
Return Air Sensor
(20K ohm
Negative
Temperature
Coefficient)
C7041 - - - - - - 4-3/16 x 2-5/16 x 1-
11/16
(107 x 59 x 43)
- -
Discharge or
Return Air Sensor
(20K ohm
Negative
Temperature
Coefficient)
C7770A1006 45 to 99 °F
(7 to 37 °C)
5% to 95%
Non-Condensing
-40 to 150 °F
(-40 to 65.5 °C)
Probe: 6 x 1/4
(152 x 6.4)
- -
Table 2. Thermostat Replacement Parts and Accessories. (Continued)
Product Part Number
Operating
Ambient
Temperature
Operating Relative
Humidity
Shipping
Temperature
Physical Dimensions in in.
(mm) Color(s)

THX9321 PRESTIGE®2.0 AND THX9421 PRESTIGE®IAQ WITH EIM
768-0311—07
* Prestige IAQ Kits and YTHM5421R1010 Kit include 50062329-001 Discharge/Return Air Sensors. Replacement Dis-
charge/Return Air Sensor part number is C7735A1000.
Occupancy Sensor
for Remote
Setback
(Requires an
Equipment
Interface Module)
WSK-24 Receiver:
- 5 to 140 °F
(-21 to 60 °C)
Door Sensor:
-4 to 140 °F
(-20 to 60 °C)
PIR Sensor:
-4 to 104 °F
(-20 to 40 °C)
- - - - Receiver:
3.6 x 3.4 x 1.2
(91.4 x 86.4 x 30.5)
Door Sensor:
1.4 x 2.3 x 0.6
(35.8 x 57.6 x 15.2)
PIR Sensor:
2.8 x 3.9 x 1.1
(71 x 100 x 28)
White
THX9421
Coverplate
(covers marks left
by old
thermostats)
THP2400A1027W
(Includes 2 cover
plates)
- - - - - - Small = 5-33/64 x 4-
21/64 (140 x 110), Large
= 6-7/8 x 5 (175 x 127)
White
THX9421
Coverplate
(covers marks left
by old
thermostats)
THP2400A1027B
(Includes 2 cover
plates)
- - - - - - Small = 5-33/64 x 4-
21/64 (140 x 110), Large
= 6-7/8 x 5 (175 x 127)
Black
THX9421
Coverplate
(covers marks left
by old
thermostats)
THP2400A1027G
(Includes 2 cover
plates)
- - - - - - Small = 5-33/64 x 4-
21/64 (140 x 110), Large
= 6-7/8 x 5 (175 x 127)
Gray
THX9321
Coverplate
(covers marks left
by old
thermostats)
50028399-001 - - - - - - 7-29/32 x 5-1/2 (201 x
140)
White
Wire Saver Module THP9045A1023 -40 to 163 °F
(-40 to 73 °C)
5% to 90%
Non-Condensing
-40 to 185 °F
(-40 to 85 °C)
- - Gray
Table 2. Thermostat Replacement Parts and Accessories. (Continued)
Product Part Number
Operating
Ambient
Temperature
Operating Relative
Humidity
Shipping
Temperature
Physical Dimensions in in.
(mm) Color(s)

THX9321 PRESTIGE®2.0 AND THX9421 PRESTIGE®IAQ WITH EIM
68-0311—07 8
SYSTEM INSTALLATION
When Installing this Product...
1. Read these instructions carefully. Failure to follow
the instructions can damage the product or cause a
hazardous condition.
2. Check the ratings given in the instructions to make
sure the product is suitable for your application.
3. Installer must be a trained, experienced service
technician.
4. After completing installation, use these instructions
to verify the product operation.
Finding Your Password (Date Code)
You will need the thermostat password to:
• Make changes to the Installer Setup.
•SetupDiagnostics.
• Perform an Installer Test.
• View Data Logs.
• Add, remove, rename or view connected RedLINK
accessories.
• Reset the thermostat to Factory Default settings.
The password (Date Code) is located on the back of the
thermostat. It can also be found by following these steps:
1. Touch Menu.
2. Select Dealer Information.
Fig. 6. Finding thermostat password.
Fig. 7. Finding thermostat password.
1324
1324
Password
(Date Code)
Dealer Informaon
OK

THX9321 PRESTIGE®2.0 AND THX9421 PRESTIGE®IAQ WITH EIM
968-0311—07
INSTALLATION OPTIONS
The THX9321 Prestige®2.0 thermostat is wired directly to the equipment. The THX9421 Prestige®IAQ thermostat is used
with the Equipment Interface Module or with a TrueZONE Wireless Adapter.
If using the Equipment Interface Module, see “Installing Equipment Interface Module (if used)” beginning on page 10.
If using a TrueZONE wireless adapter, follow the installation instructions that came with the TrueZONE, and go to
“Selecting Thermostat Location” beginning on page 12.
Guidelines for Installing RedLINK
Devices
— When installing more than one Thermostat and
Equipment Interface Module, mount the Equip-
ment Interface Modules at least 2 feet apart for
best RedLINK performance. No minimum distance
is required between the Thermostats if the Thermo-
stat is linked to an Equipment Interface Module.
— When the Thermostat is wired directly to the equip-
ment (No Equipment Interface Module and No
TrueZONE Wireless Adapter), mount the Thermo-
stats at least 2 feet apart for best RedLINK perfor-
mance.
— To determine if a RedLINK device will communicate
properly in the installed location, during the con-
nection process, press and quickly release the con-
nect button on the RedLINK device at the desired
mounting location. If the RedLINK device connects,
then it will work reliably during normal operation. If
the RedLINK device does NOT connect, try a new
location. During the connection process, the signal
is sent at low power and during normal operation
the signal is sent at high power.
— To connect a RedLINK device, make sure to press
and quickly release the connect button on the
RedLINK device. Press and holding the connect
button down too long will not allow the device to
connect.
— If you link the Thermostat to the TrueZONE Wire-
less Adapter, you will NOT be able to do the follow-
ing: control humidification, dehumidification or
ventilation, setup a program schedule remotely
from a computer, smart phone or tablet, work with
the Wireless Indoor Sensor, Entry / Exit Remote or
the Vent and Filter Boost Remote. To use these fea-
tures, wire the Thermostat directly to the zone
panel or use an Equipment Interface Module.
— If you are using a RedLINK device from a previous
installation, you must reset the device first before
you re-connect it to the new Thermostat/Equip-
ment Interface Module. See page 136 for more
information.
TM
TM
OR
THX9421 THERMOSTAT – 2 WIRES FOR POWER
RedLINK TO EQUIPMENT INTERFACE MODULE
RedLINK TO TrueZONE WIRELESS ADAPTER
THX9421 THERMOSTAT – 2 WIRES FOR POWER
THX9321 THERMOSTAT
WIRED DIRECTLY TO EQUIPMENT
OR
MCR34631
W
I
R
E
D
D
I
R
E
C
T
L
Y
T
O
E

THX9321 PRESTIGE®2.0 AND THX9421 PRESTIGE®IAQ WITH EIM
68-0311—07 10
Installing Equipment Interface
Module (if used)
If no Equipment Interface Module is used, skip to
“Selecting Thermostat Location” beginning on page 12.
NOTE: If an EIM is mounted inside a metal cabinet, such
as a commercial rooftop unit, it is recommended
to use a THM4000R1000 Wireless Adapter for
extended wireless range. Mount the Wireless
Adapter outside the metal cabinet and connect to
the ABCD terminals at the EIM. The Wireless
Adapter functions as a remote antenna for the
EIM. After it is wired to the EIM, it automatically
takes over as the antenna for RedLINK communi-
cation. For best RedLINK performance, avoid
mounting the Wireless Adapter above the roof
deck or outside the exterior walls.
NOTE: If you install more than one thermostat and EIM,
the EIMs must be at least 2 feet apart for best
RedLINK performance.
Fig. 8.
CAUTION
Electrical Hazard.
Can cause electrical shock or equipment
damage.
Disconnect power before wiring.
The Equipment Interface Module (EIM) can be mounted
vertically on the HVAC equipment or on a wall in the
equipment room.
1. Mount the EIM near the HVAC equipment or on the
equipment itself. Use screws and anchors as appro-
priate for the mounting surface..
2. To wire the EIM, strip 1/4” insulation, then insert
wires (see Fig. 9). For wiring diagrams, see “Wiring”
beginning on page 138.
Fig. 9.
Wiring 24 Vac Common
• Single-Transformer System—Connect the common side
of the transformer to the C screw terminal of the EIM.
Leave the metal jumper wires in place between R, RC,
and RH.
• Two-Transformer System—Connect the common side of
the cooling transformer to the C screw terminal of the
EIM. Remove the metal jumper wire between RC and
RH. Connect the hot side of heating transformer to RH
and leave the jumper wire between R and RC and
connect the hot side of cooling transformer to R or RC.
Selecting Discharge and Return Air
Temperature Sensor Mounting
Locations
Refer to the guidelines below and Fig. 10–14 for mounting
locations of the Discharge and Return Air Temperature
Sensors.
Selecting Discharge Air Temperature
Sensor Mounting Location
1. Mount the Discharge Air Temperature Sensor on the
supply duct in a location where the air is mixed well.
Mount the Discharge Air Temperature Sensor out of
sight of the A-Coil/Heat Exchanger when possible.
See Fig. 10.
2. When possible, mount the Discharge Air
Temperature Sensor upstream of a Steam
Humidifier, a Fan Powered Humidifier or a
Dehumidifier that is ducted to the supply. See Fig.
11–12.
3. If space does not allow a Discharge Air Temperature
Sensor upstream of a Steam Humidifier or Fan
Powered Humidifier, mount the Discharge Air
Temperature Sensor downstream of the Humidifier.
EIM
A
B
C
D
WIRELESS
ADAPTER
CONNECT
POWER
THM4000R
CONNECTED
WIRELESS SETUP
MCR32389
R
C
Y
Y2
G
L
W
O/B
W2
AUX1
W3
AUX2

THX9321 PRESTIGE®2.0 AND THX9421 PRESTIGE®IAQ WITH EIM
11 68-0311—07
See Fig. 11. When setting the Delta T Limits (see “Set
Delta T Limits” on page 89), be sure to consider the
affect that the humidifier has on Delta T.
4. If a Bypass Humidifier is installed, mount the
Discharge Air Temperature Sensor downstream of
the Bypass Humidifier. See Fig. 13–14.
Selecting Return Air Temperature
Sensor Mounting Location
1. Install the Return Air Temperature Sensor on the
return duct in a location where the air is mixed well.
Mount the Return Air Temperature Sensor
downstream of a Bypass Humidifier, Dehumidifier or
Ventilator. See Fig. 10–14.
Fig. 10.
Fig. 11.
Fig. 12.
Fig. 13.
MOUNT DISCHARGE
SENSOR HERE
M33074
HEAT
EXCHANGER
BLOWER
VENTILATOR
OR
DEHUMIDIFIER
MOUNT RETURN
SENSOR HERE
DOWNSTREAM OF
VENTILATOR OR
DEHUMIDIFIER
A-COIL
M33075A
HEAT
EXCHANGER
BLOWER
STEAM OR
FAN
POWERED
HUMIDIFIER
ALTERNATE MOUNTING LOCATION FOR DISCHARGE
SENSOR. WHEN SETTING THE LIMITS, BE SURE TO
CONSIDER THE AFFECT THAT THE HUMIDIFIER HAS
ON DELTA T.
MOUNT RETURN
SENSOR HERE
DOWNSTREAM OF
VENTILATOR OR
DEHUMIDIFIER
MOUNT
DISCHARGE
SENSOR HERE
ABOVE CENTER
OF A-COIL
UPSTREAM OF
STEAM OR FAN
POWERED
HUMIDIFIER
VENTILATOR
OR
DEHUMIDIFIER
M33076A
HEAT
EXCHANGER
BLOWER
MOUNT RETURN
SENSOR HERE
DOWNSTREAM OF
DEHUMIDIFIER
ALTERNATE MOUNTING LOCATION FOR DISCHARGE
SENSOR. WHEN SETTING THE LIMITS, BE SURE
TO CONSIDER THE AFFECT THAT THE DEHUMIDIFIER
HAS ON DELTA T.
MOUNT
DISCHARGE
SENSOR HERE
ABOVE CENTER
OF A-COIL
UPSTREAM OF
DEHUMIDIFIER
DEHUMIDIFIER
MOUNT RETURN
SENSOR HERE
MOUNT DOWNSTREAM
OF BYPASS HUMIDIFIER,
DEHUMIDIFIER OR
VENTILATOR
HEAT
EXCHANGER
BLOWER
VENTILATOR
OR
DEHUMIDIFIER
MOUNT
DISCHARGE
SENSOR HERE
MOUNT
DOWNSTREAM
OF BYPASS
HUMIDIFIER
BYPASS
HUMIDIFIER
M33078A

THX9321 PRESTIGE®2.0 AND THX9421 PRESTIGE®IAQ WITH EIM
68-0311—07 12
Fig. 14.
Installing Discharge and Return Air
Temperature Sensors
Use the following steps to mount the Discharge/Return
Air Sensors:
1. Attach plastic cover to the sensor probe.
2. Drill 1/4-inch hole for the sensor probe and mount it
to the ductwork with enclosed screws (see Fig. 15).
3. Connect wires to S1, S2, S3, or S4 terminals at the
EIM.
4. Setup the S1, S2, S3, or S4 terminals in the Installer
Setup at the thermostat.
Fig. 15. Mounting Discharge/Return Air Sensor.
Selecting Thermostat Location
Install the thermostat about 5 ft. (1.5m) above the floor in an
area with good air circulation at average temperature. See
Fig. 16.
Fig. 16. Selecting thermostat location.
Do not install the thermostat where it can be affected by:
— Drafts or dead spots behind doors and in corners.
— Hot or cold air from ducts.
— Radiant heat from sun or appliances.
— Concealed pipes and chimneys.
— Unheated (uncooled) areas such as an outside wall
behind the thermostat.
Installing Wallplate
CAUTION
Electrical Hazard.
Can cause electrical shock or equipment
damage.
Disconnect power before wiring.
The thermostat can be mounted horizontally on the wall or
on a 4 in. x 2 in. (101.6 mm x 50.8 mm) wiring box.
1. Separate wallplate from thermostat.
Fig. 17. Separate wallplate from thermostat (THX9421).
2. Position and level the wallplate (for appearance
only).
3. Use a pencil to mark the mounting holes.
MOUNT RETURN
SENSOR HERE
MOUNT DOWNSTREAM
OF BYPASS HUMIDIFIER,
DEHUMIDIFIER OR
VENTILATOR
HEAT
EXCHANGER
BLOWER
VENTILATOR
OR
DEHUMIDIFIER
MOUNT
DISCHARGE
SENSOR HERE
BYPASS
HUMIDIFIER
M33079A
M32995
5 FEET
[1.5 METERS]
YES NO
NO
NO
M19925
1324

THX9321 PRESTIGE®2.0 AND THX9421 PRESTIGE®IAQ WITH EIM
13 68-0311—07
4. Remove the wallplate from the wall and, if drywall,
drill two 3/16-in. holes in the wall, as marked. For
firmer material such as plaster, drill two 7/32-in.
holes. Gently tap anchors (provided) into the drilled
holes until flush with the wall.
5. Position the wallplate over the holes, pulling wires
through the wiring opening. See Fig. 18.
6. Insert the mounting screws into the holes and
tighten.
Fig. 18. Mounting wallplate (THX9421).
Insert Coin Cell Battery in Thermostat
Place coin cell battery in thermostat. Be sure to follow
polarity markings on thermostat. See Fig. 19.
NOTE: Coin cell battery saves time and date during a
power loss.
Fig. 19. Insert coin cell battery (THX9421)
THX9421 Installation
INSTALLATION WITH EQUIPMENT INTERFACE
MODULE (EIM)
1. Wire to C and R terminals of the EIM or to a separate
24 volt transformer (not provided). See Fig. 20.
2. Snap thermostat onto wallplate after wiring is com-
plete.
INSTALLATION WITH TRUEZONE WIRELESS ADAPTER
1. Wire to C and R terminals of the TrueZONE panel or
to a separate 24 volt transformer (not provided). See
Fig. 20.
2. Snap thermostat onto wallplate after wiring is com-
plete.
THX9321 Installation
THERMOSTAT WIRED DIRECTLY TO THE HVAC
EQUIPMENT OR ZONE PANEL
1. Refer to “THX9321 Thermostat Wiring Diagrams”
beginning on page 144.
2. Snap thermostat onto wallplate after wiring is com-
plete.
INSTALLATION WITH EQUIPMENT INTERFACE
MODULE (EIM)
1. Connect power and common from the EIM to the Rc
and C terminals at the thermostat or use a separate
24 volt transformer (not provided) to power the ther-
mostat.
2. Snap thermostat onto wallplate after wiring is com-
plete.
NOTE: Note: When the THX9321 thermostat is used with
an EIM, the relays in the thermostat do not func-
tion.
INSTALLATION WITH TRUEZONE WIRELESS ADAPTER
1. Connect power and common from the TrueZONE
panel to the Rc and C terminals at the thermostat or
use a separate 24 volt transformer (not provided) to
power the thermostat.
2. Snap thermostat onto wallplate after wiring is com-
plete.
NOTE: When the THX9321 thermostat is used with a
TrueZONE Wireless Adapter, the relays in the ther-
mostat do not function.
Fig. 20. Inserting wires in thermostat terminal screws
(THX9421).
MCR34688
R
C
1324

THX9321 PRESTIGE®2.0 AND THX9421 PRESTIGE®IAQ WITH EIM
68-0311—07 14
Mount Thermostat on Wallplate
Align thermostat to wallplate and snap into place. See Fig.
19.
Fig. 21. Mount thermostat (THX9421).
POWER OPTIONAL REDLINK™
ACCESSORIES
1. Install batteries or power the optional RedLINK
accessories.
2. If no RedLINK accessories are used, skip to “Linking
Thermostat to Equipment Interface Module (if
used)” beginning on page 15.
3. If no RedLINK accessories are used and there is no
EIM or TrueZONE Wireless Adapter, skip to “Com-
pleting Initial Setup” beginning on page 17.
Outdoor Air Sensor
1. Install 2 fresh AA lithium batteries.
Fig. 22.
Portable Comfort Control
1. Install 3 fresh AA alkaline batteries.
Fig. 23.
Indoor Air Sensor
1. Install 2 fresh AAA alkaline batteries.
Fig. 24.
RedLINK™ Internet Gateway
1. Connect power cord to an electrical outlet not con-
trolled by a wall switch.
2. Connect ethernet cable to router and the RedLINK
Internet Gateway.
Fig. 25.
R
C
MCR32937
MCR32939
MCR32938
M36568
INTERNET
POWER
REDLINK

THX9321 PRESTIGE®2.0 AND THX9421 PRESTIGE®IAQ WITH EIM
15 68-0311—07
TrueSTEAM
1. Wire and power TrueSTEAM.
2. Connect the ABCD terminals between TrueSTEAM
and the THM4000 Wireless Adapter.
3. Adjust the DIP Switches on TrueSTEAM as follows
when using the Wireless Adapter:
•DIP3:UP
•DIP4:UP
•DIP5:DOWN
Fig. 26. Powering TrueSTEAM wireless adapter.
Entry/Exit Remote or Vent Boost Remote
1. Remove the cover.
2. Insert the CR2450 coin cell battery (included) into
the slot at the bottom of the remote. See polarity
marking on the remote.
Fig. 27. Installing Entry/Exit Remote or Vent Boost
Remote battery.
3. The LED will briefly flash green. If it flashes red, bat-
tery is not good.
PERFORMING INITIAL SETUP
Initial setup options define the type of system you are
installing:
• Residential or commercial
• Non-zoned or zoned
• Used with or without an Equipment Interface Module
(THM5421)
• Used with or without the TrueZONE Wireless Adapter
(THM4000)
1. Follow prompts on the screen to select the appropri-
ate options.
Fig. 28.
NOTE: If you are connecting the thermostat to the True-
ZONE Wireless Adapter (THM4000), refer to the
TrueZONE instructions to link the thermostat and
RedLINK accessories.
Linking Thermostat to Equipment
Interface Module (if used)
1. Press and quickly release the CONNECT button on
the EIM. Make sure the Connected light is flashing
green.
Fig. 29. EIM CONNECT button.
NOTE: If the Connected light does NOT flash green,
another system may be in the listening mode.
Please exit the listening mode at the other system
and then try again.
• Green flashing: In Listening Mode. System is
ready to add RedLINK devices.
• Green steady: RedLINK devices are
communicating.
• Red: RedLINK device(s) not communicating.
Check EIM and RedLINK devices.
THM4000R1000
TrueSTEAM
MCR31476
6
543
2
ON
OFF
1
MCR33269
Next
CONNECT
CONNECTED

THX9321 PRESTIGE®2.0 AND THX9421 PRESTIGE®IAQ WITH EIM
68-0311—07 16
2. Follow the prompts on the thermostat screen until
you reach the Wireless Setup screen. See Fig. 30.
Fig. 30.
3. While the Connected light is flashing green on the
EIM, press Next on the thermostat. After a short
delay, the screen will display Device Connected.
Fig. 31.
4. Press Next, as directed on screen, to link RedLINK
accessories.
Linking RedLINK™ Accessories
Fig. 32. Connect RedLINK accessories.
1. When you see the prompt Do you have RedLINK
accessories to connect? touch Yes or No.
a. If you select No, continue to step 5.
b. If you select Yes, you will be prompted to Press
Connect on New Accessories. Continue to step 2.
NOTE: Accessories must be at least 2 feet away from the
thermostat or EIM during the linking process.
2. While the Add Device screen is displayed (listening
mode), press and quickly release the CONNECT but-
ton on each new RedLINK accessory.
NOTE: For locations of CONNECT buttons on
RedLINK accessories, see “Locating the
Connect Buttons on RedLINK Accessories”
beginning on page 18.
Fig. 33. Thermostat in listening mode.
3. After a short delay (up to 20 seconds), check the
thermostat to confirm the connection of each
RedLINK accessory.
Fig. 34. Thermostat in listening mode.
4. Touch Done at the thermostat after all new RedLINK
accessories are connected.
NOTE: The thermostat displays a countdown timer
while in the listening mode. If it detects no
activity for 15 minutes, it exits the listening
mode.
Next
Next
Done

THX9321 PRESTIGE®2.0 AND THX9421 PRESTIGE®IAQ WITH EIM
17 68-0311—07
Completing Initial Setup
5. Finish the setup by selecting the desired options.
Touch Done after you select the last option you want
to change. See “Installer Options” beginning on
page 21 for a full listing of setup options.
Fig. 35. Scheduling options.
6. The thermostat now displays its Home screen and
the thermostat setup is complete.
Fig. 36. Thermostat home screen.
Adding RedLINK Accessories to the
Thermostat
If you want to add RedLINK accessories after the
thermostat has been setup, follow these steps.
1. Touch Menu.
2. Select Installer Options.
Fig. 37.
3. Enter password (date code) and touch Done. See
“Finding Your Password (Date Code) to Access
Installer Options” beginning on page 20 for more
information.
Fig. 38.
4. Select Wireless Device Manager.
Fig. 39.
5. Select Add Device to display the Add Device screen.
The thermostat is now in listening mode.
Fig. 40.
NOTE: Accessories must be at least 2 feet away from the
thermostat or EIM during the linking process.
Installer Opons
Done
Wireless Device Manager
Add Device

THX9321 PRESTIGE®2.0 AND THX9421 PRESTIGE®IAQ WITH EIM
68-0311—07 18
6. Press and quickly release the CONNECT button on
each new RedLINK accessory.
NOTE: For locations of CONNECT buttons on
RedLINK accessories, see “Locating the
Connect Buttons on RedLINK Accessories”
beginning on page 18.
Fig. 41. Thermostat in listening mode.
7. After a short delay (up to 20 seconds), check ther-
mostat to confirm the connection of each RedLINK
accessory.
8. Touch Done at the thermostat after all new RedLINK
accessories are connected.
Fig. 42. Thermostat in listening mode.
NOTE: Thermostat displays a count-down timer while in
the listening mode. If it detects no activity for 15
minutes, it exits listening mode.
Locating the Connect Buttons on
RedLINK Accessories
Wireless Outdoor Sensor
1. Press and quickly release the CONNECT button on
the Wireless Outdoor Sensor. After a short delay (up
to 15 seconds), the thermostat will display “Wireless
Outdoor Sensor added.”
Fig. 43. Wireless outdoor sensor connect button.
Portable Comfort Control
1. Press CONNECT on the Portable Comfort Control
display screen.
Fig. 44. Portable Comfort Control connect button.
2. Press DONE on the Portable Comfort Control when it
displays “Connected.”
3. Press “No” at the next screen to save and exit, or
press “Yes” if you need to connect additional ther-
mostats to the Portable Comfort Control. See Fig. 45.
NOTE: The Portable Comfort Control can control up to
16 thermostats.
Fig. 45. Connect additional thermostats to Portable
Comfort Control.
4. Follow the same linking procedure as above to con-
nect additional thermostats.
Done
MCR28847A
MCR32942
CONNECT
WIRELESS SETUP
NOYES
CONNECT MORE?
M28482

THX9321 PRESTIGE®2.0 AND THX9421 PRESTIGE®IAQ WITH EIM
19 68-0311—07
ERROR MESSAGES:
E1 29: Incompatible device cannot be connected.
E1 34: Low RF signal. Move device to a different location
and try again.
E1 38: Make sure the thermostat, EIM, or TrueZONE
Wireless Adapter is in Wireless Setup mode, and the
Portable Comfort Control is at least 2 feet away (600 mm).
NOTE: The linking procedure will time out if there is no
keypress for 30 minutes. To begin again, press
and hold in the lower right corner of the screen
until the display changes (about 3 seconds). See
Fig. 46.
Fig. 46. Restarting the linking process.
RedLINK Internet Gateway
1. Press and quickly release the button on the side of
the Internet Gateway. After a short delay, the
RedLINK status light will glow steady green.
Fig. 47. RedLINK Internet Gateway connect button.
NOTE: The Internet Gateway must be registered online
before use at www.mytotalconnectcomfort.com.
Enter the MAC ID and MAC CRC numbers located
on the bottom of the Internet Gateway. For addi-
tional information, see instructions provided with
the device.
TrueSTEAM
1. Press and quickly release the CONNECT button on
THM4000 Wireless Adapter. After a short delay, the
CONNECTED status light will glow steady green.
Fig. 48. Connect button on TrueSTEAM wireless
adapter.
Wireless Indoor Sensor
1. Press and quickly release the CONNECT button.
After a short delay, the status light (see Fig. 49) will
glow green for 15 seconds. If the status light turns
red, the sensor did not link with the thermostat.
Fig. 49. Wireless indoor sensor connect button and
status light.
NOTE: In normal operation, the status light
remains off. If it begins flashing red, batter-
ies are low (power will be depleted after 2–3
weeks).
2. If you are installing more than 1 wireless indoor sen-
sor, give each sensor a name as you install it. Press
Name Device, as shown in Fig. 50.
Fig. 50.
Press and hold
the blank space
(or arrow may be
present)
M36571
INTERNET
POWER
REDLINK
THM4000R1000
TrueSTEAM
MCRXXXXX
MCR32934 MCR32935

THX9321 PRESTIGE®2.0 AND THX9421 PRESTIGE®IAQ WITH EIM
68-0311—07 20
3. Type the sensor name and press Done. The sensor
names are used when selecting which sensor to use
for temperature, humidification, and dehumidifica-
tion control.
Fig. 51.
NOTE: If you link more than 1 wireless indoor sen-
sor, and forget to name them, you will be
prompted to name each wireless indoor
sensor after you exit wireless setup. See Fig.
52.
Fig. 52.
Linking Entry/Exit Remote or Vent Boost
Remote
1. Press and quickly release the CONNECT button.
Fig. 53. Connect button and status light on Entry/Exit
Remote or Vent Boost Remote.
2. After a short delay, the status light will glow green for
15 seconds. If the status light turns red, the remote
did not link with the thermostat for the connection
process.
NOTE: The thermostat can work with up to 3 Entry/Exit
remotes. Each Entry/Exit remote can control up
to 16 thermostats.
NOTE: The thermostat can work with up to 6 Vent Boost
remotes.
Finding Your Password (Date Code)
to Access Installer Options
You will need the thermostat password to:
• Make changes to the Installer Setup.
•SetupDiagnostics.
• Perform an Installer Test.
• View Data Logs.
• Add, remove, rename or view connected RedLINK
accessories.
• Reset the thermostat to Factory Default settings.
The password (Date Code) is located on the back of the
thermostat.
Fig. 54. Finding thermostat password.
The password (Date Code) can also be found by following
these steps:
1. Touch Menu.
2. Select Dealer Information.
1324
1324
Password
(Date Code)