Honeywell VisionPro IAQ Programmable Universal Thermostat with Total Home Comfort Control
About This Thermostat
| MFG: | Honeywell |
| MFG#: | YTH9421C1002 |
| Our#: | 110092 |
| 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 |
. Contains all features of standard VisionPRO, except arm chair programming.
. Thermostat connects with Equipment Interface Module to control temperature, humidification, dehumidification and ventilation from a single point in the home. Only 3 wires run from thermostat to equipment interface module (EIM), making retrofitting an old thermostat a snap!
. Can control whole house humidifier and automatically raises humidity levels throughout all rooms in the home, moisturizing air to prevent symptoms of dryness and to protect hardwood flooring and woodwork.
. Can control whole house dehumidifier, and automatically lowers humidity levels through al rooms in the home, utilizing air conditioning or a whole house dehumidifier to prevent dampness, stickiness or odors; symptoms often associated with air that is too moist.
Application - Conventional and Heat Pump systems
Programmability - Universal Programming from 7 Day to Non-Programmable
Changeover - Auto or Manual
Color - Premier White®
Switch Positions (System) - HEAT-OFF-COOL-AUTO-EM.HEAT
Switch Positions (Fan) - AUTO-ON-CIRC
Power Method - Power supplied by EIM
Terminal Designations - 1, 2, 3, C, R, Rc, Rh, R, W1-O/B, W2-Aux, W3-Aux2, Y, Y2, G, L, Out1, Out2, In1, In2, Dats1, Dats2, Hum1, Hum2, Dhm1, Dhm2, Vnt1, Vnt2
Dimensions (in.) - 4 9/16 in. high x 6 in. wide x 1 1/4 in. deep
Dimensions (mm) - 116 mm high x 152 mm wide x 32 mm deep
Electrical Ratings - 20 to 30 Vac
Setting Temperature Range (F) - Heat: 40 F to 90 F; Cool: 50 F to 99 F
Setting Temperature Range (C) - Heat: 4.5 C to 32 C; Cool: 10 C to 37 C
Differential Temperature (F) - ± 1 F
Differential Temperature (C) - ±0.5 C
Stages - Up to 4 Heat/2 Cool
Outdoor Sensor - Yes, optional
Discharge Sensor - Yes, optional
Remote Sensor - Yes, optional
Sensor Element - Thermistor
Currents (Heating) - 1.0 A running
Currents (Cooling) - 1.0 A running
Currents (Fan) - 0.6A running
Operating Humidity Range (% RH) - 5 to 90% RH, non-condensing
Includes TH9421C1004 Thermostat and THM5421C1008 Equipment Interface Module
Comments - Includes Humidification Control with or without Frost Protection, Dehumidification using Whole House Dehumidifier or Air Conditioning with High or Low speed fan, Advanced Patented Ventilation Control and Advanced Dual Fuel Heat Pump Control.
Humidification Setting Range - 10 to 60% RH.
Dehumidification Setting Range - 40 to 80% RH.
ProThermostats.com Price:
$196.83
Customers most agreed on the following attributes:
Comments about Honeywell VisionPro IAQ Programmable Universal Thermostat with Total Home Comfort Control:
Product works very well! Installation was easy, but consult a professional. I especially like the outdoor temp display with the extra sensor I installed. Works great with our humidifier. The frost protection keeps frost from building on the windows during cold winter temps. Instructions and product literature are very complete.
Comments about Honeywell VisionPro IAQ Programmable Universal Thermostat with Total Home Comfort Control:
easy enough for a home owner to install and set-up.
Comments about Honeywell VisionPro IAQ Programmable Universal Thermostat with Total Home Comfort Control:
I went with this unit when I installed my new furnace. The "auto discover" recognized my 2 stage furnace and humidifier, so all I had to program was my settings. Install was a snap, we hardly needed the instructions.
Comments about Honeywell VisionPro IAQ Programmable Universal Thermostat with Total Home Comfort Control:
Installation was a breeze, just don't miss that the diagram does show the common ground being connected (C to C), like I did. I'm a total amateur and installed this thing with no problem. I hooked up the outside thermometer and the Honeywell TrueSteam Humidifier (HM509H8908) with no problem. You can buy the manual control humidifier because this thermostat does the controlling. I plan to add the ventilator at some point too.
[7 of 8 customers found this review helpful]
Comments about Honeywell VisionPro IAQ Programmable Universal Thermostat with Total Home Comfort Control:
I used this model to replace an older thermostat and a separate humidistat. As an engineer, I like the basic idea of separating the output contact module from the control display, and installing the outputs close to the furnace. I really like that the optional outdoor sensor is used to automatically adjust the humidity level in the winter. It's also very useful in the mornings for quickly seeing the outside air temp. The display also serves as a handy night light. Very easy to install and program. I also like the resetable reminders for filter, humidifier pad, and UV light replacement. It also automatically circulates air in the house, independent of heat or cooling requirements. But I highly recommend the outdoor sensor option to take full advantage of its humidity controls.
Comments about Honeywell VisionPro IAQ Programmable Universal Thermostat with Total Home Comfort Control:
Fantastic climate control with immediate monthly electric bill cost reduction.
[1 of 1 customers found this review helpful]
Comments about Honeywell VisionPro IAQ Programmable Universal Thermostat with Total Home Comfort Control:
Unit was easy to install and setup. There are quite a few settings built into the unit but manual made it simple. I use the thermostat to control our A/C, humidifier, fan (no heat). My only wish is for the cycle time for air circulation (to filter the air) was adjustable. It is fixed at a 35% duty cycle.







