Prestige IAQ Thermostat, White


Brand: Honeywell

Mfr Part#: THX9421R5021WW

Availability: In Stock
Usually ships: within 1 business day
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$207.05 / each & Free Shipping
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The Prestige IAQ thermostat is a 2 wire high definition color touch screen thermostat, 7 day programmable and selectable for residential or light commercial use. Controls up to 4-stages of heat and 2-stages of cool in a heat pump system and up to 3-stages of heat and 2-stages of cool in a conventional system. Three sets of Universal IAQ contacts to control humidification, dehumidification, and ventilation. Four sensor inputs for wired sensors or dry contact devices. Works with the Equipment Interface Module and RedLINK accessories including the RedLINK Internet Gateway, Portable Comfort Control, Wireless Outdoor Sensor and Wireless Indoor Sensor.


  • Control heating, cooling and IAQ equipment with only 2 wires at the thermostat;
  • Heating, cooling and IAQ equipment wires to the Equipment Interface Module;
  • Smart Schedule - programs in seconds for any lifestyle;
  • Patented interview based programming and installer setup;
  • RedLINK wireless communication;
  • Increase profit per job by including RedLINK accessories that provide comfort and convenience;
  • Selectable for residential and light commercial applications, meets commercial code and is title 24 compliant;
  • Light commercial - commercial language (occupied and unoccupied), schedule holidays and custom events, remote setback, economizer and time of day;
  • Delta T Alerts and Diagnostics informs customers when their system is not performing as expected with instructions to contact the dealer;
  • Provides a sense of security and greater comfort while generating repeat business;
  • All Prestige IAQ kits come standard with a return and discharge air temperature sensor to measure Delta T;
  • Alerts and User Interactions Log - Keeps a searchable history of alerts and setting changes to the thermostat to determine if there is a system malfunction or if the issue was caused by user error;
  • Saves time in troubleshooting and points the technician in the right direction;
  • Performance Logs - Keeps a history of heating and cooling performance;
  • The performance log includes Minimum and Maximum Delta T, Minimum and Maximum Discharge Temperature, Minimum and Maximum Return Temperature, Minimum and Maximum Indoor Temperature/Humidity, Minimum and Maximum Outdoor Temperature/Humidity and Run Time. Quickly determine if the system is performing as expected and reduces service time on the job;
  • Customizable Service Reminders allow dealers to remind their customers when its time to call for service, when their warranty is expiring and to provide customized alerts;
  • USB port for transferring Installer Setup, Customizable Reminders, Custom Events and Holidays to multiple thermostats;
  • USB port for adding the dealer's full color business logo on the screen;
  • 3 assignable outputs to control humidification, dehumidification, ventilation and a stage of heating or cooling;
  • 4 assignable inputs on the Equipment Interface Module can be used with wired outdoor, indoor or discharge sensors, occupancy sensor for remote setback and dry contact devices to trip pre-packaged or custom alerts such as a full drain pan or water leak;
  • Extend wireless range of the Equipment Interface Module by connecting a THM4000R1000 Wireless Adapter to the ABCD terminals;
  • Tri-lingual - English, French and Spanish display options;
  • Precise temperature control (+/- 1° F) for reliable and consistent temperature;
  • Multiple staging options to provide comfort or energy savings.

Technical Specifications:

  • Hazmat Information: UN 3091 Lithium metal batteries packed in/with equipment;
  • Application: Up to 4 Heat/2 Cool Heat Pumps, Up to 3 Heat/2 Cool Conventional Systems;
  • Dimensions (Height x Width x Depth): 3 1/2" x 4 1/2" x 7/8" (88mm x 115mm x 22mm);
  • Used With: THM5421R1021 Equipment Interface Module and RedLINK accessories;
  • Comments: Tri-Lingual Display (selectable for English, French or Spanish);
  • Electrical Ratings: 18 to 30 Vac;
  • Frequency: 50 Hz, 60 Hz;
  • Stages: Up to 4 Heat/2 Cool Heat Pumps, Up to 3 Heat/2 Cool Conventional Systems (See Equipment Interface Module);
  • Electrical Connections: Screw terminals;
  • Operating Humidity Range (% RH): 5 to 90% RH, non-condensing;
  • Supply Voltage: 18 to 30 Vac;
  • Switch Positions (System): HEAT-OFF-COOL-AUTO-EM.HEAT;
  • Switch Positions (Fan): AUTO-ON-CIRC-FOLLOW SCHEDULE;
  • Operating Temperature Range: 32°F to 120°F (0°C to 48.9°C);
  • Color: Front - White, Side - White;
  • Programmability: 7-Day Multiple Day Programming or Non-Programmable;
  • Power Method: Hardwired;
  • Terminal Designations: R, C then RedLINK to Equipment Interface Module;
  • Display Size: 8.06 sq in.;
  • Changeover: Auto or Manual;
  • Setting Temperature Range: Heat - 40°F to 90°F (4.5°C to 32.0°C), Cool - 50°F to 99°F (10°C to 37.0°C);
  • Humidification Setting Range: Cooling - 40 to 80% RH, Heating - 10 to 60% RH;
  • Dehumidification Setting Range: 40 to 80% RH.
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Location: 5407 Foster Ave, Brooklyn, NY 11234