Hooking a heating only t-stat [for out door wood stove] to electronic t-stat thought I could connect red and greeen to heating t-stat .Sounded good but ac condensing unit comes on,not just the blower on furnace .thinking problem ls the electronic t-stat I don't understand why this wouldn`t work must back feed through electronic t-stat and pick up ac relay on furnace control board any ideas thanks Vern