[wingnut60]

Glenn,
Are you using the furnace and/or space heaters? If you are using the furnace a lot, there should be a 2" flex duct hanging loose in the area behind the doors that may help to aim it down into the area where the tank line comes from. Somehow cold air gets to the area (duh) and some warm air needs to be directed there. Man, what a hassle this type of fight is...how does the song go? When it's springtime in the Rockies, it's 40 below!