Conducted comprehensive inspection of 17-year-old Carrier furnace to assess safety and reliability. Major components (igniter, flame sensor, blower wheel/motor, draft motor) tested functional, however multiple holes were identified in the heat exchanger rendering the unit unsafe to operate. Combustion analysis results were acceptable, but heat exchanger deterioration appears age-related. Discussed replacement options with homeowner, including heat exchanger replacement versus full system replacement. Documentation provided for customer decision-making.