Honeywell TH4110U2005/U T4 Pro Program Mable Thermostat, White

OMG. It was so easy to install and the instructions were very straightforward. It worked the first time after I plugged in the FAU.Easily programmable. Well-made.😀

Works great

Simple, programmable stat. I changed batteries on my old one and the backlighting disappeared. Set this one up in minutes, mounted it to my old base and there you go.

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.

Easy to install and works well

I know several HVAC technicians who frequently install these theromostats due to their ease of use, reliability, and cost. Easy to install, simple to setup using the included instruction manual, and very easy to program for 4 times of day: Sleep, Wake, Away, and Home. Have your heat turn down at night with Sleep, have it kick up a few degrees before you Wake so that the house is warm while you get ready, it drops down again when you're Away, and kicks back up before you come Home. Super easy to figure out and we definitely saved money on our heating bill this winter because of it.

**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.

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.