Honeywell VisionPro IAQ Programmable MultiStage Thermostat with Total Home Comfort (YTH9421C1002)
. 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.
Comments about Honeywell VisionPro IAQ Programmable Universal Thermostat with Total Home Comfort Control:
Great device but does not have the option to display extra temperature sensors as individual devices. The only option is to average the temperature across all the devices.
8/11/2011
5.0
One of the best
By fireguy50
from Lansing, MI
About Me Handyman, Homeowner, Professional
Pros
Energy saver
Intuitive Controls
Precise Controls
Cons
Requires extra wiring
Best Uses
Comments about Honeywell VisionPro IAQ Programmable Universal Thermostat with Total Home Comfort Control:
The VisionPro IAQ has so many features, I believe its better than the internet thermostats that need to micromanage it via cell phone. Automatic change over from heat to cool in the spring & fall. Automatic humidity control in the winter and will use the AC to dehumidify in the summer even if it isn't hot enough for AC. Can add additional sensor in the house, and run multiple zones in the house.
2/16/2011
5.0
Well Designed Contol Unit
By KR
from Buffalo, NY
About Me Homeowner
Pros
Easy To Adjust
Easy To Install
Intuitive Controls
Precise Controls
Cons
Best Uses
Homes
Comments about Honeywell VisionPro IAQ Programmable Universal Thermostat with Total Home Comfort Control:
Works well with my Lennox variable rate furnace. The air temp seems to be more consistently warm. Furnace for the first time seems to operating at true modulation rates other than 40%. Now the range of modulation from the furnace are readings between 40 to 90% even with 1% increments. The furnace internal logic seems to responding to the control.
1/25/2010
5.0
Great product
By Engineer
from Colorado
About Me Homeowner
Pros
Easy To Adjust
Easy To Install
Intuitive Controls
Precise Controls
Cons
Best Uses
Central Controls
Homes
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.
2/14/2009
5.0
best on the market
By mark
from ohio
About Me Homeowner
Pros
Easy To Install
Intuitive Controls
Cons
Best Uses
Homes
Comments about Honeywell VisionPro IAQ Programmable Universal Thermostat with Total Home Comfort Control:
easy enough for a home owner to install and set-up.
12/27/2008
5.0
Easy install, user friendly
By Fixerupper
from Chicagoland
About Me Homeowner
Pros
Easy To Adjust
Easy To Install
Intuitive Controls
Precise Controls
Cons
Best Uses
Homes
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.
12/1/2008
5.0
Love it.
By Ed the DIYer
from Leonardtown, MD
About Me Homeowner
Pros
Easy To Adjust
Easy To Install
Intuitive Controls
Precise Controls
Cons
Best Uses
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.
4/19/2008
(7 of 8 customers found this review helpful)
4.0
Excellent features & smart modular appro
By Driftwood
from Brookfield, IL
About Me Handyman, Homeowner
Pros
Easy To Adjust
Easy To Install
Intuitive Controls
Cons
Best Uses
Homes
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.
4/15/2008
5.0
Great Product
By Jim
from Lyford, Texas
About Me Handyman, Homeowner, Professional
Pros
Easy To Adjust
Easy To Install
Intuitive Controls
Precise Controls
Cons
Best Uses
Central Controls
Homes
Large Rooms
Offices
Small Rooms
Comments about Honeywell VisionPro IAQ Programmable Universal Thermostat with Total Home Comfort Control:
Fantastic climate control with immediate monthly electric bill cost reduction.
4/11/2008
(1 of 1 customers found this review helpful)
5.0
Great thermostat
By wxlidar
from State College, PA
About Me Homeowner
Pros
Easy To Adjust
Easy To Install
Precise Controls
Cons
Best Uses
Homes
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.
