Your home’s furnace runs reliably every time you turn it on for years. Yet, even with good maintenance and upkeep, these systems will become inefficient and, in some cases, may even fail. Knowing when to replace your furnace (rather than just repairing it) isn’t always easy. It’s best to allow a trusted technician to offer some guidance and direction to you about when the best time to replace it is. Here are some signs that you may want to do this soon.