If the control was just replaced a couple of months ago, it is highly unlikely that it is bad again. Where do you live? Check to make sure snow is not blocking the pipes outside. Do you hear any water girgling at the dripleg,which is where the condensate comes from the furnace? Do you have a/c and do you have a round thermostat? Sometimes the heat off cool switch fails to make contact. When it locks out do you see a green light flashing? When it starts does it start right away or does it spit and sputter? There are several things that can cause this problem. Was the heat exchanger pressure tested, it needs to be done every 4 years as well as the air flapper needs replaced.