Many homeowners aren’t familiar with the telltale signs that their furnace needs to be professionally maintained or repaired. Simply recognizing the indicators early can prevent many of these technical problems from getting worse, and ensure that you return to solid furnace performance as quickly as possible. With certain issues, these signs come in the form of specific sounds. If you notice any of the following three noises coming from your furnace or HVAC system, the time has come to contact a local HVAC professional: