A:Answer Hi Marianne,
I'm no expert but it appears your Tstat has batteries, mine did too, the Honeywell does not have batteries and relies on the 24 volts supply from the Furnace circuit board. There also needs to be a spare wire in your wire loom to the T-stat. Mine had this so I just connected it to the t-stat and the furnace circuit board. There was a wiring diagram int the furnace compartment that told which connector was the constant 24 volts supply. Hope this helps and please read all directions carefully. You are responsible for your own connections. Good luck!