Directions a bit over complicated/ confusing, but easy common sense 2 wire hookup. Used to replace/ upgrade old type mercury switch in older home. I bought 2, one for each floor/ zone. No programming crap to deal with and simple 2 screw install. Both working well. Also has on/ off switch on side which is handy. Obviously turn power off at boiler first before hooking up.
Rating:
[5 of 5 Stars!]