Spec Sheet
Table Of Contents
- Application
- Features
- Contents
- Specifications
- System Installation
- Installation Options
- Guidelines for Installing RedLINK Devices
- Installing Equipment Interface Module (if used)
- Wiring 24 Vac Common
- Selecting Discharge and Return Air Temperature Sensor Mounting Locations
- Selecting Return Air Temperature Sensor Mounting Location
- Installing Discharge and Return Air Temperature Sensors
- Selecting Thermostat Location
- Installing Wallplate
- Power Optional REDLINK™ Accessories
- Performing Initial Setup
- Linking Thermostat to Equipment Interface Module (if used)
- Linking RedLINK™ Accessories
- Completing Initial Setup
- Adding RedLINK Accessories to the Thermostat
- Locating the Connect Buttons on RedLINK Accessories
- Finding Your Password (Date Code) to Access Installer Options
- Installer Options
- Making Changes to Installer Setup
- Installer Tests
- Operation
- Setting the time/date
- Setting the fan
- Setting system mode
- Preset Energy-Saving Schedules
- Adjusting program schedules
- Overriding schedules: residential use
- Overriding schedules: commercial use
- Viewing equipment status
- Setting vacation hold: residential use
- Setting holiday/event schedules: commercial use
- Setting custom events: commercial use
- Setting holiday schedule: commercial use
- Setting holiday override: commercial use
- Initiating occupancy mode: commercial use
- Remote setback: commercial use
- Adjusting humidification settings
- Adjusting dehumidification settings: residential use
- Adjusting dehumidification settings: commercial use
- Adjusting ventilation settings
- Customizing screen color
- Setting preferences
- Cleaning the thermostat screen
- Adjusting security settings
- Viewing dealer information
- Advanced Features
- Installer options
- Using the temperature display
- Using the humidity display
- Universal Outputs (U1, U2, U3)
- Universal Inputs (S1, S2, S3, S4)
- Alerts and Diagnostics
- Heat Pump and Backup Heat Operation
- Indoor Air Quality (IAQ) Control
- IAQ Reminders
- Customizable Reminders
- USB Port
- Commercial Features
- Overriding schedules: commercial use
- Setting holiday/event schedules: commercial use
- Setting custom events: commercial use
- Setting holiday schedule: commercial use
- Setting holiday override: commercial use
- Initiating occupancy mode: commercial use
- Ramp Rates
- Custom Names
- Remote Setback
- Economizer and Time of Day (TOD) Operation
- Pre-Occupancy Purge
- Battery Replacement
- Optional Accessories
- Portable Comfort Control
- Remote Indoor Sensors
- Backup Control
- Replacing a Thermostat
- Replacing an Equipment Interface Module
- Wiring
- EIM Wiring Diagrams
- THX9321 Thermostat Wiring Diagrams
- THX9321 Thermostat Wiring Diagrams Using Universal Relays to Control Heating or Cooling
- Wiring IAQ Equipment or a Heat/Cool Stage to the Universal Terminals
- Economizer Module Wiring Diagrams
- Wiring C7089U1006 Outdoor Sensor
- Wiring guide — Wired Indoor Sensors
- Zoning
- Troubleshooting
- Regulatory Information
THX9321 PRESTIGE
®
2.0 AND THX9421 PRESTIGE
®
IAQ WITH EIM
105 68-0311—07
Fig. 218.
Dehumidification - Residential
The thermostat reads the indoor humidity level and allows
the user to set a dehumidification setting. The thermostat
controls the humidity level using the cooling system or a
whole house dehumidifier.
If humidification and dehumidification are setup to
operate in the same system mode (Heat, Cool, Off) and
you are sensing humidity from one location, the
thermostat will automatically enforce a 15% deadband
between the humidification and dehumidification
settings. The thermostat will automatically switch
between humidification and dehumidification to maintain
the desired humidity level.
If humidification and dehumidification are setup to
operate in the same system mode (Heat, Cool, Off) and
you are sensing humidity from two different locations
using a remote wireless indoor sensor (for example, main
level and crawl space), the thermostat will allow
humidification and dehumidification to operate at the
same time, and there is no deadband between
humidification and dehumidification settings.
Dehumidification using the Cooling
System
When set for A/C with Low Speed Fan or A/C with High
Speed Fan, an overcooling limit can be set from 0 °F to 3
°F (ISU 9070). The thermostat uses the cooling system to
reduce humidity by lowering the temperature up to 3° F
below the current cool setpoint until the desired humidity
level is reached.
If set for A/C with Low Speed Fan, configure U1, U2, or U3
as normally open or normally closed (ISU 9050) and wire
to the Low Speed Fan terminal on the equipment. For
example, if the U1, U2, or U3 terminal is normally closed, it
will open when the thermostat calls for
dehumidification.See “Wiring IAQ Equipment or a
Heat/Cool Stage to the Universal Terminals” beginning on
page 152.
NOTE: The thermostat will not lower the fan speed when
the second stage of cooling is on.
Dehumidification Fan Speed Priority
If the house has circulation issues to certain parts of the
house when running in low speed, this feature will allow
the thermostat to use the high speed fan more often so
that the conditioned air has better circulation within the
home.
Press MENU
Scroll to select HUMIDIFICATION
Set humidity to desired level
Window Protection
limits the amount of
humidity to prevent
frost or condensation
on windows
Press More Settings to set:
• Window Protection Setting
• Review humidifier pad or
clean tank / water filter
timer