Diagnose Sudden HVAC Airflow Loss to Half Strength

Cost Savings

Checklist Tasks

• Check all supply and return vents for obstructions or closed registers.
• Inspect the air filter for clogging or collapse and replace if needed.
• Examine blower compartment for coil ice buildup indicating refrigerant or drainage issues.
• Test blower motor amperage against specifications for failing components.
• Inspect flexible ducts for kinks or crushes that severely restrict airflow.
• Use a smoke pencil at return grilles to spot hidden duct leaks or blockages.
• Check evaporator coil for dust, mold, or debris restricting airflow.
• Listen for unusual blower or duct noises indicating obstructions or part failure.
• Verify thermostat fan is set to ‘Auto’ to avoid masking intermittent drops.
• Ask about recent renovations that could block or disconnect ductwork.
• Inspect condensate drain pan for overflow that could trigger safety shutoff.
• Confirm all zone dampers open and close in response to controls.