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Location: 185 Price Parkway, Farmingdale, NY 11735
Hours: 8:00AM - 7:00PM, Mon - Fri.
This product does not comply with the "Safe Drinking Water Act,"
which requires that products used in any system providing water for human
consumption (drinking or cooking) to meet low-lead standards.
Please check the box below to confirm you are aware of that this item is for non-potable water applications only.
This product will NOT be used in the installation or repair of a potable water (human consumption) application.
You must agree to this statement in order to purchase this product.
Do not use this item for any installation or repair of potable water applications.
This product does not comply with the "Safe Drinking Water Act,"
which requires that products meet low-lead standards in order to be used in systems providing water for human consumption (drinking or cooking).
This item is for non-potable (non-human consumption) water applications only.
This product was discontinued by the manufacturer.
Install Instructions (with Equipment Interface Module)
Install Instructions (VisionPRO IAQ)
Stages describes the number of heat or cool sources that you need to control with a single thermostat.
Voltage, or volts, is a measurement of the difference between two electric fields (in heating terms, the difference between the Earth's electrical field and the electricity running through your wires).
Amperage, or amps, refers to the amount of electricity flowing through the wires.
Wattage, or watts, is the amount of electrical power that an appliance uses or generates.
The Honeywell TH9421U touch screen universal programmable thermostat provides electronic control of 24 Vac heating and cooling systems of 750 mV heating systems in addition to humidification dehumidification and ventilation.
(based on 20 reviews)
of respondents would recommend this to a friend.
Reviewed by 20 customers
Displaying reviews 1-10
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from Newbury Park, CA
Comments about VisionPro IAQ Thermostat & Module:
I have been looking to replace a failed Totaline Thermostat that would control the Carrier gas heating/AC system in my home along with the whole house humidifier. I have tried several other models including a replacement unit from Totaline(the original model Intellistat has been discontinued) but none of them would allow me the flexibility to control a powered humidifier when the system called for heat while continuing to give me the option to use the humidifier with the furnace blower to raise humidity levels without heat when needed. I had the local HVAC guys who installed the system several years ago come out twice only to tell me it could not be done(while charging me $180 dollars!). I scoured the Internet to find a thermostat/humidistat with the ability to manage this task and came across this wonderful unit. After reading the specs and other reviews, I ordered from PEX online due to their outstanding reputation and return policy and am thrilled to say this little guy works perfectly! I installed the unit and interface module myself in about 30 min, programmed it using the easy to follow setup instructions, and voila! It works perfectly, it's easy to read given the large backlit display and I now have full control over my heating, AC and humidity all in one package!
Bottom Line Yes, I would recommend this to a friend
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nice piece of equipment
By old E.E.
easy to program, very easy to install, saves money
A necessity to your high effiency system
By Lindquist Electric
from Upton, MA
Great product. Was simple to install and program. Only took two hours from beginning to end. I even had to run a new wire to my T stat location because it's currently only doing 1 stage heat (2 conductors) so I needed 1 additional conductor. The fact that all the accessories or features are wired at the module makes it a clean install and easy to add to. It's currently controlling a humidifier and 2 stage furnace and is equipped with the outdoor sensor which is a must. Will be doing AC soon and possibly a heat exchanger. Will be easy to add to programming.
Great product and great price from Pex
By Bill J.
HVAC contractor installed, same 3 wires as original thermostat, separate box mounts at furnace, complements Carrier ICS Infinity furnace perfectly. Benefits of thermostat are useless without outdoor temperature sensor, must have
Would buy this again
from Indianapolis, IN
I bought this thermostat because I wanted to replace our existing themostat with something that could control both the furnace and and humidifier. It took a little time to get all of the settings right, but so far it's worked great. The only drawback is that since this model doesn't come with the outdoor temp sensor I have to manually adjust the humidity when the temperature drops to keep condensation off the window panes.
Merchant response: The outdoor temperature sensor is available here: http://www.pexsupply.com/Honeywell-C7089U1006-Outdoor-Temperature-Sensor-4955000-p
I would buy this product again
from kansas city ks
more accurate control of temp than a old mercury style thermostat
There's good and bad
from Prior Lake, MN
I purchased it to control the heating, air conditioning AND an HRV. The heating subcontractor said no one makes such a thermostat. That's not his only error, and I'm still fixing things.GOOD: Great display, easy to setBAD: The painter bumped it and it fell and broke. When you remove it from the box it comes apart hard - but on the wall it doesn't hold together as well. I bought another unit and loosened the back plate on the wall and the main module is holding better. (the screws had bowed the back slightly)I have not connected the HRV yet.It probably has an "anticipater" function - I want more differential action.I'm assuming that most of the problems are mine and the added ignoramce of the heating sub.
Tough installation - great device.
from Collierville, TN
I bought this to operate a furnace, air conditioner and whole-house humidifier. It does all this well. You can progam the heating and cooling for individual days and set the desired humidity. It also has options for outdoor and additional indoor temperature sensors. The problem is that Honeywell does not want individuals installing this product but only approved contractors. The literature they give to contractors instructs them to use the device to sell additional equipment such as humidifiers/dehumidifiers etc which the device can control. The installation instructions are very minimal so you need to have some knowledge or assistance to get this up and running. The wall thermostat is simple enough but hooking up the control module to the various equipment you want to control can be a challenge depending on what you have. Using some online DIY forums and some trial and error I got things working without causing any damage. I needed to buy some thermostat wire in order to complete all the connections from the control module to the existing circuit board. The only problem is the backlight on the thermostat works only intermittently. I contacted Honeywell but other than telling me to check the connections they only would say hire a professional installer. I recommend taking good notes on all your existing connections prior to installing this so you can go back to where you were if you don't get it right. The major challenge for me was getting the humidifier (which was professionally installed) functioning properly. In retrospect I should have bought this thermostat first then had the humidifier installed. It took me several hours but I got everything functioning correctly though I don't have any HVAC experience.
The best price [...]
from Atlanta, GA
First of all I have to admit that I'm one of the stupid persons who has thought that all thermostats are same. So why I would shell out $$$ to a digital t-stat as any other may do the same job. Actually this may be a right thought process if you would like to shell out your $$$s to the gas company as well as compromising your comfort level. This is what I have done for last three years until I've understood the value of having a heat pump as well as understanding a heat pump is a pain in the butt without a very smart thermostat. If you have a heat pump, and want to maximize your your comfort level, VisionPro IAQ is the way to go. This product is one of the best value for my money I spent on. VisionPro IAQ also helped tremendously to accommodate comfortable humidity level at my home even though I had a digital humidistat from another respectable brand. Installation is very easy thanks to smart design of the IAQ. I'm so glad to get the best t-stat with a very good price [...]
from Farmington, MN
Bought this because:-7-day programable (You can set WAKE, LEAVE, RETURN, SLEEP temperature settings everyday)-Touch screen-Controls my Aprilair Humidifier and can set my humidity level(manual previous)-Can set to recirculate air to keep more even temp on multi-levels-Can control zone heating/air-Outside Temp displayed on thermostat with sensor-Furnace and humidifier filter reminders (you set the days and it tells you based on days of use)-No extra wires run to thermostat-Very user friendly and gives user a lot of optional preferences during set-up like screen light on always or on touch, etc.-Too many features to listOnly negative, my installer said these don't work that well to control the Air Exchangers and recommended to leave that controlled as it is. This unit only allowed it to either be on an on/off cycle switching every 20minutes or manual on/off. Air Exchanger control already on the wall and it works by it self the way it should so just left it. Also, installer mentioned not to use "frost protection" on unit when controlling a humidifier as in his experience it never turned the humidifier on so just disable that feature on set-up and it'll just set the humidity level % to what you desire like 35%.I see this unit now all the time in commercial buildings but works great in residential too.I did hire a professional to install as I thought I could do it as I'm very handy at a lot of things but did not want to screw it up in the dead of winter plus it looked like a larger project than I wanted to tackle. Took installer 2 hours to install with an outdoor sensor. Make sure they've installed this unit before as it is more technical than others. He had my furnace panel off and wires run from it to the Module as well as wires from thermostat, outdoor sensor, and humidifier to the module so think about hiring a pro as recommended.
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