Repair the system if it’s under about 10–12 years old, the repair is a small part (capacitor, contactor, motor, drain), or the failed component is still under parts warranty; replace it if the repair quote multiplied by the system’s age in years comes to more than about 5,000, if it needs a compressor or evaporator coil out of warranty on an R-410A or R-22 system, or if it’s the second major repair in two seasons. Those rules resolve most cases; the table below handles the rest.
The $5,000 rule
Multiply the repair quote by the age of the system in years. Under 5,000, repair; over, replace. A $600 fan motor on a 6-year-old system is 3,600: repair. A $2,200 compressor on an 11-year-old system is 24,200: replace. The rule is a proxy for two things that actually matter, remaining life and repair frequency, so treat it as a first pass and check it against the factors below.
Age and expected life
Central AC and heat pumps typically last 12–17 years in North Carolina’s climate; heat pumps run year-round and tend toward the shorter end, and coastal salt air shortens outdoor unit life further. Past 12 years, efficiency has drifted down and the next major failure is closer than the last. How long systems last has the detail by type.
Refrigerant
Systems installed before 2025 use R-410A; new ones use R-454B or R-32. R-410A remains legal to service, but its price has climbed steeply as supply is phased down, so leak repairs, coil replacements and compressor jobs that open the refrigerant circuit on an older system cost meaningfully more than a few years ago and will keep rising. That doesn’t mean a working R-410A system needs replacing; it means an out-of-warranty refrigerant-side repair on one is a stronger replacement signal than the same repair used to be. R-22 systems (pre-2010) are almost always a replace. The refrigerant transition explained.
Warranty
Check the parts warranty before you decide anything. Many compressors and coils carry 10-year parts coverage if the system was registered at install; under warranty you pay labor and refrigerant only, which turns a $3,000 job into $1,000–$1,500 and usually tips toward repair. Out of warranty, run the $5,000 rule and get a replacement quote to compare.
Decision table
| Situation | Usual answer |
|---|---|
| Any age, small part (capacitor, contactor, drain, thermostat) | Repair |
| Under 10 years, major part under parts warranty | Repair |
| Under 10 years, major part out of warranty, otherwise healthy | Repair, but get a second opinion on the diagnosis |
| 10–15 years, refrigerant-side repair (leak, coil, compressor) on R-410A | Get a replacement quote; usually replace |
| 15+ years, any major repair | Replace |
| Any R-22 system needing refrigerant work | Replace |
| Second major repair within two seasons | Replace |
| Comfort or bill complaints alongside the repair (humidity, hot rooms) | Replace, and fix sizing/ducts while you’re at it |
Compare real numbers, not rules
The AC repair cost page has current ranges by part; the AC replacement cost and heat pump cost pages have current installed ranges, and in North Carolina the rebates on heat pumps can shift a close call decisively. Whichever way you go, start with a contractor whose license we’ve already checked in the registry and, for a major repair on a mid-life system, ask a second one to confirm the diagnosis.