I have a Honeywell, #RTH230B programmable thermostat, but it is not following its program. Manually, it works fine. I have changed batteries. Is there some way to totally reset it, to fix it?

Open and disconnect the face completely, remove the battery. Reassemble after a few minutes, this is like a hard re-boot. You will need to re-enter you whole program. To save time try just re-entering one program change rather than the whole deal.