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

https://precision-always-ready-sac.lucialpiazzale.com/escalating-repair-costs-reveal-why-fixing-a-dying-system-costs-more-than-replacement

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