E04
Airflow Obstruction
The system has detected restricted airflow, indicating blocked ductwork, dampers in wrong position, or obstructed vents. This reduces system efficiency and can strain motors.
- Blocked or closed supply/exhaust vents
- Crushed or kinked ductwork
- Debris blocking outdoor intake or exhaust
- Dampers stuck in closed position
- Ice buildup at outdoor terminals in winter
- E04 error code displayed
- Weak airflow from vents
- System runs louder than normal
- Whistling or rushing air sounds
- Motors running hot
Check all indoor vents are open and unobstructed
Inspect outdoor intake and exhaust for blockages (leaves, snow, ice)
Verify all dampers are in correct open position
Remove any furniture or objects blocking vents
Clear snow or ice from outdoor terminals
Inspect accessible ductwork for kinks or damage
Important: If these steps do not resolve the issue or you are uncomfortable performing them, contact a professional HVAC technician immediately.
- Monthly visual inspection of outdoor vents
- Keep outdoor terminals clear of vegetation and debris
- Seasonal check of all damper positions
- Professional ductwork inspection annually
How do I locate all my HRV vents?
HRV systems typically have intake and exhaust vents in bathrooms, kitchens, and utility rooms. Check your HRV installation manual or contact us for a system diagram.
Can blocked airflow damage my HRV?
Yes, prolonged airflow restriction forces motors to work harder, potentially leading to premature motor failure. Address airflow obstructions promptly.
Need Immediate Assistance?
Our expert technicians are available 24/7 for emergency HRV repairs. Don't let error code E04 disrupt your comfort.