We have a three-zone system on our propane furnace. Wood stove heats the top two floors, and we leave the basement un-heated unless someone is down there (kids playing or wife sewing). Problem is we forget to turn it off when we come upstairs. Is there a thermostat with a motion sensor that simply turns off after 15 minutes of inactivity? I don't need the fancy "learning" tstat that tries to learn your schedule, etc. I only want two modes, "Hold heat to 68" and "Off". No setback, no A/C mode, no daily or weekly schedule.