As a general rule, if your HVAC system is more than 15 years old, you should consider replacing it. As your HVAC system ages, it will require increasingly frequent repairs. And while repairs don’t cost that much individually, the costs can quickly add up. That’s why, in the long run, getting an HVAC replacement makes both practical and financial sense.  Important note: Keep in mind that infrequent maintenance can drastically shorten your HVAC system’s service life. As a general rule, your system should be inspected and maintained at least twice a year.  Other than keeping track of your HVAC system’s service life, how can you tell if the system needs to be replaced? By keeping an eye out for the warning signs below.