A Minnesota furnace works hard. Once the cold settles in, it may run day after day through long stretches of freezing weather, snow, wind, and below-zero nights. That is why timing matters when it comes to furnace maintenance. For most homeowners, the best time to schedule furnace maintenance in Minnesota is early fall, before the heating season is in full swing. A fall furnace maintenance appointment gives you time to have your system checked before you depend on it every da