When the time comes to replace your old gas furnace with a newer, more efficient, and better working model, the conditions usually warrant a speedy decision.

You may find yourself suffering through a cold Baltimore night, huddled under blankets, with a somewhat disgruntled family. You want a warm home and you need it now!

Knowing the precise time to replace your gas furnace would be ideal, but more often than not, your unit simply stops working. It may happen to you with seemingly no advance notice.

But if you look and listen carefully, there may be some sign of an impending need to replace your old unit with a more efficient and better operating one.