How to replace my Jantrol thermostat with a Hunter one

You start by researching to see if that stat will control your furnace or boiler, they must be compatible.

I would recommend not buying a hunter. If you all ready did then turn off the power to your unit. Then take your old t-stat off the wall look at the wire to terminal color code and write it down. Then chck to make sure you new t-stat has the same terminals. If so it will match just fine.