I installed a Honeywell 34 last month, no problems encountered. Honeywell has a 1-800 hotline, called ref the progammable features and they were a great help. Although if your sched changes I don't recommend the 34 it has an "Intelligent Recovery System". It gets messed up if you change the programming like I have to, but you can turn it off. These electronic stats will keep your house at a more even heat than the mercury ones, trust me.