I just moved into a 2 year old house with two carrier thermostats, one upstairs, one downstairs. I can not seem to keep the house evenly heated. Any advice?

Do you have separate heating systems or zones? If it is all one heating system, it is either going to be on or off. What kind of a system is it? Do you have any dampers or balancing valves? We have some good people here. With a little info, we should be able to help.