HoneywellYTHX9421R5085WW/U Prestige IAQ Kit with Redlink technology

Up front I am not one that usually writes reviews, but I am "that guy" that researches items very thoroughly (probably too much at times if you ask my wife)...That being said, we had to replace our entire HVAC system due to age and it slowly turning into a "money-pit". We knew we wanted a smarter thermostat with the ability to control its settings remotely. We looked at Nest and the offerings from Trane and determined that the Honeywell Prestige was out best bet. Why you ask?:Nest: Was a nice unit and will appeal to the Iphone crowd, the way it is programmed is what turned me off. You change it for 7 days, it learns your patterns and sets up the schedule for you. Kinda cool but I like to have more control over the settings.Trane: Extremely overpriced for what was essentially a re-branded Honeywell ($600+) - and it wasn't as good as the Prestige.The package we chose included the EIM and the Prestige Thermostat, the EIM is the interface to the HVAC equipment. It was perfect for us since we were installing from scratch and rewiring everything was in the plans anyway. Once installed the initial programming of the EIM and Thermostat took a long time (there are several cryptic HVAC jargon based settings to be made and the installers took care of that part). The homeowners section of the programming offered everything you could want to change, heat, cool, humidifier, schedule, color of the screen, etc in an easy to understand menu. There are a huge array of options with this device, I will tell you that...so if you are a control freak, look no further this is the one for you.There are additional purchases that have to be made to allow remote changes through the mobile app, a redlink internet gateway (around $90.00) is required to make that connection to the outside world. You have to connect that device to your interet connection and to both the honeywell website and your new thermostat - it sounds hard but it takes 15 minutes tops and its really easy with good instructions.Optional items we purchased for our own comfort are: a remote outdoor temp sensor that the thermostat uses to modify when it starts heat and cooling cycles to conform to your schedule, a remote indoor sensor that helps balance temps in one of the colder rooms in the house and a remote thermostat that we can use to set the temp in the master bedroom (another cold room). All of the items connected via WiFi to the thermostat and are really nice additions to the setup.This is a great setup and laden with options, I don't think you can go wrong with this setup. My only qualm is not being able to look at system performance reports from the thermostat on my PC. You can look at them on the thermostat screen, but it would be nice to use a bigger screen to see them - keep in mind this may be possible and I just don't know how to do it yet so I didn't remove any stars...-A

Uniquely, the Prestige includes return duct and discharge duct temperature sensors, which can be used to track performance difference over time! Why is that important? If the temperature difference increases over time, its telling you that efficiency is dropping, which could indicate a leak in your ductwork or weather sealing, or even a loss of insulation (blow-in insulation can compact ever time)Optional indoor temperature/humidity sensors, plus an outdoor temperature/humidity sensor, allow you to control dining room temperature for a dinner party, or average the bedrooms at night, or control by kitchen temp when you're cooking, You can control by temperature and/or humidity.Unlike many thermostats, the Prestige can automatically shift between heating and cooling modes.The Next has no external sensors whatsoever. The Ecobee3 offers an indoor sensor but its temperature-only (and Ecobee forces you to buy them two at time). That lack of sensor flexibilitym okus the lack of control,The Prestige splits the thermostat into two parts. The color touchscreen is wireless and needs only a power connection. You can move it to any room you want. Several other control devices are available including internet control. You can put one control unit in each room if you wish.The "brains" is the Equipment Interface Module. It mounts near the blower and communicates wirelessly with the control unit(s) and sensors.If you have the Internet interface, the system can be set to monitor performance using the duct sensors. It can be set to send an email or text alert if performance falls outside a norm you set.Other features include dehumidification that works with even with a single speed blower. A recirculate feature turns the fan on about 30% of the time, mixing the air while saving money over the constant ON fan setting. It can be set to automatically come on early in order to reach a given setpoint at the time you specify.Numerous RedLINK and wired accessories are available. My guess is that the favorite is the THM6000R1002 Internet Gateway which is needed for remote control via smartphone or laptop, as well as for performance alerts by email and SMS. The gateway is not needed for Honeywell's own wireless products, whic; they use the Prestige's built-in RedLINK wireless.Other options are the C7189R1004 indoor and C7089R1013 outdoor temperature/humidity sensors. You can set the Prestige to use the average of all the indoor sensors, or use just the sensor(s) you specify (we prioritize the bedroom and living/dining room sensors.) The outdoor sensor allows weather conditions to be displayed on the thermostat, and is used by the thermostat to determine whether to use heating or cooling mode (you can set this manually if you prefer).Lastly, it can control Honeywell humidifiers using humidity information from the thermostat and remote sensors.Bottom line, if you have a heat pump, you don't want Nest or Ecobee constantly juggling temperature for you. In most instances this will cost far more than maintaining a constant temperature. More important to me was the ability to optimize comfort in the most used rooms, and to monitor system performance. Nest lacks any ability to monitor the performance of my HVAC. Only Honeywell can remotely monitor temperature and humidity, indoor as well as out, combining that data to maintain indoor temperature and humidity the way I choose, not how some programmer thinks I would choose.

It works very well. Items needed for a 5 star rating.1. Ability to see current status of the system, running or standby.2. Ability to change the vacation schedule so that the system can be restarted on the way home in case of early or delayed return.

I need to buy ANOTHER part in order to control the thermostat with the app. And the settings are heat, cool, off. Would love to have one that has an automatic option. I am shocked at how poorly described this was. I wanted something to help with the humidity and while I gained that, I lost app control and automatic heat or cool all for $260! Very disappointed.

Easy to wire and excellent control of sensors and HVAC equipment. Installation only took an hour or so to install heat pump, two stage furnace, duct sensors, 2 inside sensors and 1 outside sensor. Everything was working and kept the house comfortable for nearly two days. I got up in the morning on the second day and the house was 62°F. I looked at the thermostat and it said the heat was on. I went down stairs and took the cover off the connections and the LED for the blower was green but the blower was not on. I shut the system down and checked continuity of the green G Wire. Then I removed the green wire and connected it from the G terminal to the R terminal and when I turned the system back on the system brought the temp up to 70°F. Then I turned the system off again put the green wire back on the G terminal and turned the system on to find only 1-2 VAC when the blower was activated and not the 24 VAC that would trigger the blower. I put the old thermostat back and ordered a brand new Prestige 2.0 IAQ from Honeywell.