Bests & Worsts Reviews from Amazon

I wanted a simple to install thermostat to replace the aging, mercury switched Honeywell items that control our heat and cooling. After researching I decided that a simple weekly timer is good enough, and certainly better that what we had originally. The RTH221B shows the current temperature and can be set to adjust the temperature when you wake, leave, return and night. It is simple to use with 15 minute increments. Installation says "15 minutes or under" and I found this to be true. To install: Turn off power to furnace and thermostat (although it is a low voltage feed, you MUST still do this) Unscrew the original thermostat from the wall but leave wires attached Check the color of the wires and which terminals they attach to on the original (look for small letters W,R,Y,Rc etc) Mark the wires (if needed) with the stickers provided in the package Unhook wires from the original Remove backing plate from new thermostat, thread wires through hole and place against wall Attach backing plate using screws and wall plugs provided Put 2 x AAA batteries(NOT supplied)in the faceplate Attach previously marked wired to the matching terminals at the back of the faceplate Snap faceplate onto backing plate Read instructions for setting time and programs Turn power to furnace back on Pros: cheap, easy to install, good instructions Cons: would have been nice to include 2 x AAA batteries Overall a good buy. I fitted one as a test and then bought 3 more.