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

https://precision-hvac-evaluation-sac.almoheet-travel.com/know-your-system-s-age-before-deciding-repair-or-full-replacement-today

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