Have had wacky times explaining the Infinity T'stat to homeowners. These are usually tech savy people. Once they press and hold the ADVANCED button for 15 seconds you open up a can of worms. These home owners try to ask, analyze and quantify every feature and reading logged in this stat. FYI, that little ECM inducer HUMS at 4000 rpm. Seem to get nuisance calls about them. Ask them if they hear it only when they stand 3 feet from the furnace. Answer- Yes. So I can only reply to stand futher away from it:-)
Get the Carrier dealer to match you up properly and do a top-notch install.