Honeywell Home T9 Smart Thermostats with Sensor: WiFi, HomeKit Compatible, Touch Screen, 7-Day Programmable, Alexa & Google Assistant

Wired right as per Honeywell support. warm air with honeywell, very cold air with Old Ring thermostat.

It's a great tstat when it works. I have had multiple times watching it reset. Sometimes it just turns off and I get up and pull it off to reset it. I'm probably going to get a power monitoring meter with data recording so I can prove to honeywell that the Stat socks and it's not the furnance.

The heating and cooling functions work fine but if you need a thermostat to control ventalation or a humidifer using a U1 or U2 connection, this is not the one for you. While the wiring diagrams and images on this site show it has U1 and U2 wire connectors, when I received my thermostat, it does not. The installation instructions say very clearly it will not work for U wire connections. So... which is it? It is very misleading to show the connections. Had I not needed to use the new thermostat for heat because it was -4 degrees outside and I was going out of town, I would have definitely returned it just because I don't appreciate the inaccuracy, whatever the reason.

I have used T9 thermostats on my two Carrier HVAC units since 2020. Two issues: 1) On HVAC unit #1 there is a large temperature overshoot when heating. For example, assume the set point is 73 F. The temperature shows 73 F when I hear the furnace stop firing. But by the time the fan stops the temperature reaches 77- 78 F. I wish that there was a tuning parameter that I could adjust to make the furnace kick off a bit sooner so as to reduce the overshoot. The performance when cooling is reasonably good. 2) On HVAC unit #2 the T9 reboots almost every cycle at about the time that the set point is reached. The T9 on HVAC #1 rarely reboots. The company that installed my HVAC units says that rebooting is the fault of the thermostat. On the plus side, the display is great - easy to read. And the APP is very good. For me, I've learned to live with the T9's limitations. However I would be reluctant to recommend it.

Worked OK for a few years, now is complete garbage. At least once an hour it goes into a bright white screen with a spinning wheel on it. Then it loses its' mind daily and gives me an error wanting me to set the date and time, but will not let me adjust it. When it does this it is no longer following the schedule, just whatever the last set temperature was. Now I have a junk thermostat and a couple of useless sensors since these are only compatible with this thermostat.

It was pretty decent when it worked. Just look online for T9 wifi issues, it's absolutely garbage and will disconnect itself. Support will tell you they're "working on it"

Been running this thermostat for a out 9 months. It's better than not having a remote sensor, but has major firmware/software issues. No ability to calibrate the sensors (which are not very accurate). I had 2 next to each other and they registered a 3-4° difference. The temp regulating function also lags significantly before actually sending signals to the A/C.

Out of the blue, four years after purchasing, the main unit stopped being connected the same way to our system and to the app. We used to have a "dual" option (for both heat and a/c) on the master unit. It could be set as "if the temperature reaches x, cool. If the temperature reaches y, heat." This was one of the things we LOVED about the thermostat. Having a two zoned home with TWO of these (a master and a "dependent" thermostat) it's important that they both function the same. This time of year in New England, there are days that we set this dual temp setting to a 15 degree range and let things go. Having it just disappear is awful! Plus, the random cycling of the system all night keeps me awake. It's for the birds. This really picked up mid-March. Time to toss anything Honeywell, in my opinion, and report my concerns to the state department of Energy.

I have one in each of our homes, and they are awesome. I can monitor the tempature when I am away and set vacation tempatures to save money.

It’s awesome wish I would have changed my thermostat sooner it keeps the house much cooler in summer haven’t used in winter yet just had it installed this summer.

Do not buy this thermostat. Go with ecobee. The sensors don't work either.

I have a new T9 thermostat but I live in the UK and would like a wiring diagram with more detail than what is in the product book as it’s really not the best.

I have no complaints about the thermostat, it works well and as described, but two concerns: 1) It came with an adaptor for those whose wiring in the box does not contain a "C" wire. My home has been updated, so the box contained a C Wire, and I am left with a gadget I don't know what to do with. I don't just want to put it in the garbage and send it to the landfill. 2) Overall, the product came in 500% more packaging it needs. Again, I have to send a lot of material to a landfill. This product does not require nearly this much packaging.

Its Too good and efficient to use so its really value

I was really excited about installing two of these thermostats with the extra room sensors for each level of my house. However, within two weeks of installing, we realized it was triggering our aux heat constantly. It would only be 40 degrees out and we would adjust the temperature by 1 degree and the aux heat would come on. I contacted support and they advised I adjust some settings which I did but it didn't fix the problem. I threw out the boxes since I was initially happy with them before realizing they were regularly triggering our aux heat and raising our electricity bill instead of lowering it like smart thermostats are advertised to do. I removed them and reinstalled our old "dumb" thermostats to avoid our aux heat coming on all the time and now I am stuck with two T9s that were a waste of money. Don't buy if you live anywhere where it gets to 40 degrees or lower on a regular basis in the winter...I live in Virginia so its not like I live in a very cold place.

I have a problem with the internet connection loose at my lake house and it is 190 miles away. It is very difficult for me to reset my thermostat from home. I bought the unit so I could use it from home.

While I am satisfied with the product as a hole, I cannot understand why a design feature has failed, why support only offers circular reasoning, and they cannot fix the issue. The feature that can send an email if an under/over temp or humidity problem exists, sends that email, using a light gray font on a white background that can barely be read indoors and completely impossible outdoors. Support says that cannot be fixed. Perhaps they should discontinue that feature altogether as it is useless. If this is not important to anyone, then the T9 is a good choice.

We purchased the T9 after months of research due to our kids rooms being to 🥶 or 🥵 when our main bedroom was just right. Once we got that and added the additional sensors boy were we in zones for real, we were able to measure and balance the temperature off of their rooms combined and kept everything nice comfortable with our killing our electric and gas. We have even recommended it to family members who have the similar experience.

Purchased T9 in 2022 because of its sensor. 2nd floor was never cool in summer, with Central AC, prior to T9. This summer, using the T9 menu options, I had the option of using its sensor (2nd floor) or main thermostat (1st floor) to determine temp of home. By selecting its sensor, the 2nd floor was so cool. Thank you Honeywell!

You say that user can buy up to 20 remote sensors for the T9 stat.... But... user can NOT SEE the remoted sensor activity/temp on the phone APP. That must really prevent a lot of sensor sales for you guys... ECOBEE shows every sensor on the system clearly, while remote user is using the APP