Upon reaching 12 to 15 years, compressor and capacitor failures account for most HVAC breakdowns

https://precisionhvacrepaircorner.huicopper.com/undersized-systems-cost-1-500-to-4-000-in-premature-compressor-failure-without-manual-j-standards-1

A properly maintained HVAC system typically lasts 12–15 years, but component-level failure—especially compressor breakdown or capacitor burnout—often determines actual lifespan well before that