The last thing anyone needs is for their furnace to start blowing cold air — especially in the winter. But what causes this problem, and how can you fix it?

GRAND RAPIDS, Mich. -- With the frigid temperatures that are only going to get colder in the next few days, furnace repair people are busy fixing broken heating systems all around west Michigan.

Gas furnaces are a common heating solution in Frisco homes, providing reliable warmth during cold months. While generally ...