Bests & Worsts Reviews from Amazon

I installed two of these (one for each of our systems). 30 days later, I have noticed the systems not running as often as previously since the program settings prevent them from being set too low (by "unauthorized" family members) for long periods! I have also noticed the house "feels" comfortable more often than previously. They have FOUR programmed time settings WAKE-AWAY-HOME-SLEEP. Just set the temp and start time for each range. Here's an example for cooling (times in 24 hour and temps in F but you can set for AM/PM and C): WAKE=0630 TEMP=73 AWAY=0800 TEMP=75 HOME=1700 TEMP=73 SLEEP=2230 TEMP=72 Time periods can be set differently for each weekday but will be the same for both the weekend days. Time periods can be skipped as well (e.g. you can set it to have only HOME & SLEEP modes on weekends). If someone changes the setting, the temperature returns to the programmed setting when the next time period is reached. Using above settings as an example, if in AWAY mode and user drops setting to 72, unit remains at 72 until HOME time period at which time temp returns to 73 and then follows the programming cycle as outlined. The instructions are very straight forward and easy to follow. I suggest taking a picture of your existing wiring as well as writing it down to insure no mistakes. BE SURE TO TURN OFF BOTH your existing thermostat AND the BREAKER to your air handler before installing to avoid any shorts/etc. while changing wiring! Once batteries are installed, units can be set up on bench top and then just plugged into the wiring. It was nice to have them all set up when I was ready to install rather than having to make all those adjustments on the wall. Units come pre-programmed to "learn" how your system responds and will turn on before time periods to insure temperature setting is reached by the time period start time. This feature can be disabled if desired and the instructions identify how to do this. Finally, units can be programmed to display a reminder to change the AC filter. The reminder can be based on run time or calendar days elapsed. Very nice units at a reasonable price. I highly recommend to anyone who wants to get a little better control over their HVAC operation while still allowing family members to make "temporary" comfort adjustments.