HoneywellTH4110U2005/U T4 Pro Program Mable Thermostat, White

I am very impressed by the design and build quality of this thermostat. The wiring ends use the perfect tool-free method for attachment and detachment. Comes with comprehensive information for multiple applications. Uses extremely low battery current and can be wired to supplied current as well. Very well thought-out product.

I replaced a very old (55 years) analog thermostat with this new system. I wanted a modern digital controller for forced air heating and cooling, programable, but without the need to connect to Wi-Fi, and compatible with older wiring that does not include a C wire (hence the need for batteries). Installation was straightforward. There are a host of settings that can be reviewed and changed, if need be, but the defaults work fine, or at least they did for me. There are YouTube videos to help, and the one detail question that I had about my specific wiring setup was answered with a quick phone call. It is understandable that the manufacturer would prefer a professional install, but they do everything they can to help the DIY homeowner if that is your preference. Recommended, works great.

I've been very happy with this thermostat - while I haven't been programming it thus far, it's been so much easier to use than the old analog unit, the display is great - so easy to see the most important info right away and I like that overall, it's a simple unit that seems to have proven reliable - I did not care for all the bells and whistles that come with pricier units as I don't have use for them.

Programmable scheduling without overkill features that I would never use or need. Simplicity was key but some install aspects could of been clearer. This thermostat does the job but in many cases and at least in my application the advanced setup options (ISU) was required! The ISU required two changes. I have heat pumps and in the ISU section of the software I needed to select heat pump and select the number of filters.The program schedule key presses is significant in the number of presses. I found I needed to play around with it a couple of times to feel confident. You can have any where from 1-4 events each day. You can also remove and add back in any of the events.Installing the wires was easy. You will have no option for emergency heat or aux source which I have never used so that was okay for me.So far after 2 days I found this thermostat to be pretty accurate and improved over my past Honeywell unit. Temperature remained slightly more steady. Apparently, the adaptive intelligent recovery (AIR) found in the ISU is helping. One caveat related to your program scheduling and AIR. If you set your schedule start time at say 9 am the AIR will anticipate the need to start up 15 minutes earlier. Good to be aware and you may want to change your start time by the 15 minutes.

Able to install in less than 10 minutes. My system is for heat only, so there are only 2 wires, but for a more complicated system, it is still very easy.There is a plastic surround that will cover up the old hole, which is great if needed.The Programming is quite easy to use. After a few days I had to re-program and reduce the temperatures across the board as the heat sensor was a bit higher than my old thermostat.Overall, I recommend this device.

**This works with a millivolt system!**It was not clear from the product page or other reviews, so I took a gamble on this and connected it to my millivolt system. I connected R to my TH terminal, W to my TP terminal, inserted the two included AA batteries and it Just Works.The mounting plate expects the system's wires to exit through the wall - mine were routed outside the wall from my ancient gas furnace. I filed a channel in the plate to route the wires from the outside in.

My plumber had given me the information for this brand but the non programmable version and I got this one, which is programmable for him with the same model numbers. He thought it was perfect and will update what he uses as a result. I have a 104 year old house with a gas furnace that runs a steam radiator heating system. This is all that’s needed and the programming is like the older version I had that wore out after 10ish years. Looks better, reads room temps properly and when winter comes should be fine. If not I will update, otherwise highly recommend for easy install over older version.

Overall a nice unit. Comes with a large plastic plate which covers the existing hole. Easy to install and wire up. The drawback - a bit tricky to program. It is very flexible but will require a lot of button pushing and cycling through menus.