Forced-Air / Split / Packaged
Low Airflow Troubleshooting
Airflow-first diagnostic for weak supply airflow, high Delta T, iced/sweating coils, noisy returns, and room comfort complaints when the blower runs but delivered CFM is low.
Safety Notice
Disconnect power before opening blower or electrical panels. Moving blower wheels and live electrical are present. Iced coils may indicate refrigerant issues — EPA 608 required for refrigerant work. Wear appropriate PPE.
Confirm the low airflow symptom
Verify the airflow complaint before measuring. Look for: weak airflow at multiple supply registers, high Delta T across the coil, noisy returns or whistling grilles, an iced or sweating evaporator coil, or rooms that won't condition even though the blower is clearly running. This workflow assumes the blower is expected to run — if the blower isn't running at all, use the blower-not-running workflow.
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