Residential HVAC inspection checklist

Check that the unit sits level on a stable surface, has clean condenser coils, operational fans and motors, properly insulated refrigerant lines, and adequate clearance around all sides. Also verify the electrical disconnect is accessible and operational, and check refrigerant levels using appropriate gauges. These items ensure efficient operation and prevent premature system failure.

To check refrigerant levels, attach manifold gauges to the service ports while the system is running. Compare the pressure readings with the manufacturer’s specifications for the specific refrigerant type. Abnormal readings may indicate a leak or improper charge. Remember that handling refrigerants requires proper certification, so document your findings but leave adjustments to qualified technicians.

Check for visible signs of air leakage at duct connections, including dust streaks, disconnected sections, or damaged insulation. Use your hand to feel for air escaping at joints while the system runs. For thorough assessment, consider using smoke pencils near suspected leak areas or recommend a duct blaster test. Properly sealed ducts should show no air movement at connection points.

Verify that high-pressure cutoff switches, flame sensors, limit switches, and carbon monoxide detectors are functioning correctly. Test the thermostat’s emergency heat function if applicable. For gas systems, check that the gas shutoff valve is accessible and that flame rollout switches are operational. These safety devices prevent dangerous operating conditions that could damage equipment or harm occupants.