A:Answerwork with 4 wire,but not without (C)wire,power extension kit (PEK) have to be installed at your furnace.PEK is included in the box.easy to install if follow correctly instructions.if you'r lost,got some good installation video on yt
A:Answeryou got on this thermostat three options,winter(only furnace,summer,only a/c or auto, which both of furnace and a/c are activated,if you adjust do desired temperature,it will keep it day and night automaticaly.
A:AnswerGreat question! Here is more info about installation with a boiler system: https://support.ecobee.com/s/articles/Heat-Only-2-Wire-Boiler-Furnace-Wiring-Diagrams
A:AnswerYou can do one of two things: if the bolt a conductor cable to your present thermostat has a spare lead, and there is a C terminal at the furnace, you can collect up AC wire. The second thing you can do is used to see wire adapter that comes standard in the box with the ecobee.