> Honeywell Prestige IAQ Comfort System - YTHX9421R5002

Honeywell Prestige IAQ Comfort System - YTHX9421R5002

Honeywell Prestige IAQ Comfort System - YTHX9421R5002

About This Thermostat

MFG: Honeywell
MFG#: YTHX9421R5002
Our#: 176410
Programmable: Yes (7 Day or Non-Programmable)
Stages: 4H & 2C
System Compatibility: Multi-Stage, Heat Pump, Single Stage, Heat Only
Power Options: 24 VAC Hardwire
Heat/Cool Changeover: Automatic or Manual
Programmable Fan: Yes
Temperature Limits: Yes
Keypad Lockout: Yes
Backlight: Yes
Vacation Hold: Yes

Honeywell Prestige IAQ Comfort System - YTHX9421R5002

The Prestige IAQ thermostat provides control of 24Vac of heating and cooling systems. RedLINK enabled to work with compatible wireless accessories.  Only 2 wires are required to connect thermostat and equipment interface module.

This Prestige IAQ Thermostat Kit contains 

THX9421R5005 Prestige HD Color Touchscreen Thermostat
 - THM5421R1005  Equipment Interface Module

Control this thermostat over the internet with the new RedLINK Internet Gateway


  • Large, easy-to-read full color display shows current indoor temperature and humidity, temperature setting, date and time on the home screen. Also displays outdoor temperature and humidity on home screen (if wireless outdoor sensor is installed)
  • Controls multistage equipment, humidification, dehumidification and ventilation all with only 2 wires at the thermostat location
  • Customizable Service Reminders allows the contractor to have automated messages direct homeowners to a screen with the contractor's full-color company logo, phone number and website.
  • Change Reminders to inform it is time to replace air filter, humidifier pad or ultraviolet bulb or batteries in RedLINKT connected devices.
  • Adjustable backlight level allows thermostat to be on full brightness at all times or dim to the brightness level of choice when the thermostat is not being used
  • Interview-Based Programming wizard to easily and confidently schedule thermostat temperature and times
  • USB Port allows downloading of installer settings to quickly and consistently perform setup of thermostats in similar applications
  • USB Port allows easy setup of dealer logo and contact information on thermostat screen
  • Real-Time Clock keeps time during power failure; automatically updates for daylight saving time
  • Precise Temperature Control (± 1 F) for reliable and consistent temperature
  • Multiple HOLD options allows modification of schedule as needed
  • RedLINKT Enabled to communicate with compatible wireless devices

Description - Prestige IAQ Thermostat Kit controls Humidification, Dehumidification and Ventilation Control
Application - Up to 4 Heat/2 Cool Heat Pumps
Application  - Up to 3 Heat/2 Cool Conventional Systems
Programmability -  7-Day Multiple Day Programming or Non-Programmable
Changeover - Auto or Manual
Color - Arctic White
Dimensions (in.) -  3 15/16 in. High, 6 7/8 in. Wide, 1 1/2 in. Deep
Switch Positions (System) -  HEAT-OFF-COOL-AUTO-EM.HEAT
Switch Positions (Fan) - AUTO-ON-CIRC
Power Method - Hardwired
Terminal Designations -  R, C then RedLINK to Equipment Interface Module
Electrical Ratings - 18 to 30 Vac
Frequency  - 60 Hz
Frequency - 50 Hz
Electrical Connections - Screw terminals
Operating Temperature Range (F) - 32 F to 120 F
Operating Temperature Range (C) - 0 C to 48.9 C
Setting Temperature Range (F) - Heat: 40 F to 90 F; Cool 50 F to 99F
Setting Temperature Range (C) - Heat: 4.5 C to 32.0 C; Cool: 10 C to 37.0 C
Humidity Setting Range  Cooling: 40 to 80% RH. Heating: 10 to 60% RH.
Stages - Up to 4 Heat / 2 Cool Heat Pump or Up to 3 Heat / 2 Cool Conventional
Operating Humidity Range (% RH)  - 5 to 90% RH, non-condensing
Includes  THX9421R5005 Thermostat and THM5421R1005 Equipment Interface Module
Comments  Tri-Lingual Display (selectable for English, French or Spanish)
Used With  RedLINKT enabled thermostats and accessories
Display Size - 8.06 sq in.
Humidification Setting Range - 10 to 60% RH.
Dehumidification Setting Range - 40 to 80% RH.
Voltage - 18 to 30 Vac