Goal: Ensure proper airflow throughout the system by inspecting filters, ductwork, and blower components
Locate and inspect the air filter:
- Find the air filter (usually in return air duct or air handler)
- Remove the filter and hold it up to light to check for dirt accumulation
- Check the filter size printed on the frame (e.g., 16x25x1 inches)
- Expected result: Filter condition assessed and correct size identified for replacement
Test airflow at supply vents:
- Use a tissue paper or anemometer to test airflow at each supply vent
- Hold tissue 6 inches from vent - should be drawn toward vent with strong airflow
- Test all vents throughout the house to identify weak or blocked airflow
- Expected result: Strong, consistent airflow from all supply vents
Inspect accessible ductwork for damage:
- Look for disconnected ducts, air leaks, or physical damage
- Check duct insulation for tears or missing sections
- Look for obstructions like debris, animals, or collapsed sections
- Expected result: Ductwork integrity verified with no major leaks or damage
Test blower fan operation and airflow:
- Temporarily restore power and set thermostat to fan-only mode
- Listen for smooth blower fan operation without grinding or squealing
- Check airflow strength at the return air grille - should have strong suction
- Expected result: Blower operates smoothly with strong airflow throughout system
Inspect blower compartment and motor:
- Turn power back OFF and access the blower compartment
- Check blower wheel for dirt buildup or damage
- Inspect motor bearings and drive belt (if equipped) for wear
- Expected result: Blower components clean and in good mechanical condition
Replace air filter with correct specification:
- Install new air filter matching exact size and MERV rating
- Ensure airflow direction arrow points toward the blower unit
- Secure filter access panel properly to prevent air bypass
- Expected result: New filter installed correctly with proper airflow direction
If weak airflow from vents: Check for clogged filter or blocked return air
If blower makes noise: Clean blower wheel or check for loose components
If some vents have no airflow: Check for disconnected ducts or closed dampers
You'll know you're done when: Airflow system is fully inspected and optimized for proper operation
- Air filter replaced with correct size and MERV rating
- All supply vents tested and showing strong airflow
- Accessible ductwork inspected for leaks and damage
- Blower fan operation tested and running smoothly
- Blower components cleaned and in good condition
Ready for next step? You've ensured proper airflow and can now inspect the outdoor unit and heat exchange components.