'ole wrote:
The furnace does not "always" follow the thermostat programming. It
initially follows the thermostat setting of say 20 degrees, first
thing in teh morning, but after getting to 20, the temp drops off and
it hovers around 16 degrees.

Most likely a poorly designed thermostat. What brand / model is it?
http://www.honeywellcannon.com/Desig...te%20Paper.pdf