Maybe it’s been a while since you’ve thought about your furnace. After all, you haven’t needed it all summer! But it’s best to consider it now, so you can get any repairs done—or schedule replacement if necessary—before you’re left with a freezing home in January, trying frantically to get someone to come to fix or replace your furnace in a hurry. How can you tell if furnace repair or system replacement is the right choice? Here are some key things to weigh while you make that decision.