Summer has already come to an end and fall is upon us, which means leisurely days of pruning rose bushes are quickly being replaced by necessary fall maintenance. We all know how cold it can get during those Michigan winters and you surely don't want to suffer the consequences of a home that's unprepared. But while you're cleaning gutters and putting away garden hoses, have you stopped to check on your furnace? When the temperatures are soaring in the summer, we can sometimes forget just how important our furnace is to us and frankly, it may be starting to feel a little neglected. Here are six great reasons your furnace most likely needs a tune-up before the next big chill.