The 800- 468-1503 was all of the numbers visible to my search on the thermostat without prying it open, which I did not want to do. The thermostat serves my heat pump which was programmed for "comfort" setting when initially installed. It is now on "economy" setting. (and I'm not sure how I got it changed). My wish is now to reset it back to "comfort". It is a Honeywell, digital, with the number ???? 800-468-1502. If we can solve this online, GOOD. If not , I'll get the installer back for help.