Lux Pro P621U-010 Programmable 5-1-1 Day Thermostat, 2 Heat, 1 Cool, Batteries Included

TX9100Ua and TX9100Uc (This First review was in Early 2015 I think)This economical unit is Excellent and a Real Bargain to boot. It has every feature we needed- is inexpensive, easy to program, easy to use, has a good downloadable instruction manual, first rate build quality and has a responsive US based technical help line that really does help!We are refitting our old Church steam heating system with Programmable thermostats and wanted units without the "Hold" feature. For a home the Hold is very desirable, but for a multi-building institution which is used by many different people we didn't want someone to set the Temperature up to 74- press Hold and forget to reset it- thus heating the unoccupied space for days or weeks. We couldnt find one- but we were able to modify this unit to suit our needs.The 4 front buttons are a resilient semisoft plastic that push through to the membrane switches mounted on the circuit board. You can remove the 8 small screws holding the circuit board to access this strip of soft buttons. Then a neat razor trim of the Hold and Setback buttons can set them back below their front panel openings. Scraping off the Front label leaves no trace. But the hold and setback features are still available if needed by pressing the newly indented buttons from the front with a small screwdriver.We bought 3 of these from Lowes and 1 from Amazon- same model number but they were not the same.The Lowes units had a number ending with "a" and the Amazon unit ended with "c" but the packages didnt show that difference- and it is significant. The "a" unit has a "Duration" setting (60, 30, 20, 10 etc) which sets the time in minutes between the cycles. One unexpected behavior with the duration type is that the unit comes on at the preset duration time even if the thermostat is satisfied- then it turns off after a brief "ON" period. For most applications this would be OK but it wasn't ideal for our system which uses large motor valves which dont like to be turned on and off quickly. The "c" unit uses a "Swing" number from 1 to 9. The Swing is the +or - temperature between on and off- and each numeral is equal to one quarter degree F. So if you want your heating to come on at 69 and go off at 71 then set the Swing to 4- setting it to 8 would give 68 to 72. Both "a" and "c" units have a maximum load rating of 1.5amps per terminal and 3.0amps total Maximum load.For us, this meant using a control relay to supply the 1.8amps our motor valves need. (this relay is not needed for normal home use - and it is certainly not a defect in the Thermostat)There are 4 temperature changes per day allowed- LUX labels them Morn, Day, Evening and Night but they canbe any time but must be at least 15 minutes apart. Thus 4 to 4:15AM , 4:45 to 5:15AM and 8 to 8:45PM and 9 to 11PM would work.Things we like-Presettable max or min temperature that limits the Temp the front Arrow buttons can reach (we set ours to 74)Special program feature- which you can set for your system to go to another daily program for 1 to 30 days-IE Vacation.Lockable settings to prevent anyone changing the program or settings unless they know the 4 digit code.Something we wish- that there was a way to lock the program (as well as the Hold and Reset buttons) but leave the UP/ DOWN arrows available for temporary temperature adjustments by the occupants . Having that change would make this unit 100% PERFECT!PS: We can hear no "buzz" with any of our 4 units.Update- October 2017- we now have 8 of these T'Stats and still are happy with them overall- but have just encountered a problem where one of the first installed units lost its time and day setting. We ordered a replacement .for it and found that the battery holder which previously depended on spring tension to maintain contact is now soldered to the circuit board. Experimenting with another early unit found we could make it lose its time and day setting by slightly twisting the circuit board. We believe that LUX discovered this weakness sometime back and made the appropriate design change to correct it. Our fix was to make the same easy repair to each of our old units (you have to clip off the small white plastic bridge on each end of the battery holder and then carefully solder the silver contact down to the circuit board using rosin core solder of course).Units purchased currently probably do not need this fix. Hope this helps someone with misbehaving older units.I still give them 5 stars for all the reasons mentioned above- plus this new evidence of ongoing attention to a quality problem. Good job LUX!

This worked perfectly with my model of furnace. The install was simple to understand and to do. Programming was easy to use. I like this model much better than the older Lux model that it replaced. When I made the change I had my doubts about how the different display would work out. But it is easy to read even in moderate/low light without needing to use the back-light. The current temperature uses large numbers for easy reading.

I've been wanting my own programmable thermostat for years now, but apartment living has been a damper to that ... so this is the first unit I've owned. It's nice and appears to work and comes at a decent price, but it's not that user friendly.Installation was fairly easy. As a new home owner, my opinion on this may be somewhat tainted in that I haven't done a lot of around-the-house labor to have a good scale of difficulty built up, but then again, if I can do it, it's probably pretty simple. I have VERY limited electrical wiring experience, but the instructions are clear enough in this regard to walk you through it. And they include 6 diagrams for the 6 most common home HVAC wiring schemes, with each of those including possible variations on wire labels. My biggest complaint here is that the included paper instruction manual is basically a single large sheet of paper that is somewhat confusing and extremely simplistic. The included manual does make it clear that the full manual is available online as a PDF, but the problem is that they tried to include both the installation and the operation instructions on the one sheet of paper ... if you're going to omit material and tell someone to go to the website to read the whole thing, at least include all of the INSTALLATION instructions. Along with that, there wasn't much help in trying to sort out what type of system your house might have (if say, you've only lived there a month).Operation is a little more wonky. My complaints here are not about functionality ... in fact, this programmable thermostat has quite a few features for something so reasonably priced. I actually didn't expect things like "smart recovery" (where it learns how long it takes the HVAC to reach the desire temperature, then starts it up BEFORE the desired time so that the desired temperature is reached ahead of time) or filter reminders. The problem is that the actual user interface and the methods by which you interact with the thermostat are not intuitive or friendly. The basics are obvious enough, but for things like accessing display features or system running customization, it becomes something of a chore that will require you to check the manual. For example, just to change something like temperature display (Fahrenheit or Celcius), you have to set the HEAT / COOL switch to off, then hold NEXT for 5 seconds, which pops up a series of VERY simply worded phrases that amount to a number and a short-hand, and you have to scroll through these from beginning to end, with no jumping forward or backward option. This is the case for most of the program features. One lucky break: the thermostat includes a COPY feature, which lets you copy an entire day's worth of programed temperatures and times to another day. Without this, it would take you a good 10 minutes or more just to program the 4 periods of the 7 days.So while I highly recommend this thermostat for the reasonable price and various programmable features, along with the 7 day format, be aware that it is not easy to interact with, and you'll probably need to consult the manual anytime you need to change something other than the current temperature.-- EDIT: As a quick pointer, I notice that this thermostat, or maybe it's just thermostats in general, does not like rechargeable batteries. It seems there is some kind of voltage problem, as it shows as full for about a week or so, then suddenly the battery is dead. However, when I use standard one-use AA batteries, it works fine ... and in fact, I haven't replaced the batteries for well over a month now. --

The media could not be loaded. Very good product very easy to set it up it takes only 5 minutes works great perfectly as a backlight as you seen the video is a blue backlight great product great price

Easy setup ...go online for more in-depth instructions. So far it's great works for my pellet stove of 24v also works for millivolt pellets stoves ....swing temp setting is vital for pellet stoves thats where Honeywell is a poor product

This product works very well. The backlight is much more even than others I have owned, making it much easier to read from a distance. The fact that you can set the temperature spread was the deal-maker for me, and because of that feature it works so much better than the previous thermostat, which was turning the stove on and off too rapidly.There are just two small reasons that I give it 4 stars instead of 5:1) I wish the display were a bit larger to better see from a distance -- the big current-temp digits are large enough, but the rest are too small to see except when close up; and2) I find the programming is not entirely intuitive. The basic daily programming is easy, but other features are not. For example, the EMER button is poorly named, positioned, and described in the manual -- one section of the manual says it has no function without a heat pump while another section explains how it accesses certain setup functions. It is the first thermostat where I have found myself regularly reading the manual to recall how to do something. This is not a deal-killer because once you have the settings how you want them you can just forget it. I'd still buy this model again in spite of this because it really has a wonderful array of features, even if they are a bit difficult to access.

Worked exactly as expected, easy install, good instructions for programming.

Cheaply made. Not the same rigid construction as the previous one. Has that look and feel of cheap “made in China “ construction. Not satisfied at all.

Exactly as advertized and expected. Arrived quickly. Easy to install in about 20 minutes. Works great with combination gas furnace and air conditioning.