Your kitchen exhaust fan is one of the most important components of your fire protection system. When it stops working properly, grease builds up faster, smoke fills the kitchen, and fire risks increase dramatically. Knowing the early warning signs can help you avoid breakdowns, violations, and costly emergencies.

Below are the most common signs your exhaust fan needs professional service.

🔊 1. Loud Noise, Vibration, or Rattling

If your exhaust fan starts making:

• Grinding noises
• Rattling or banging
• Heavy vibration
  …it means the motor, bearings, or fan blades may be worn or loose.

Operating it in this condition can cause complete motor failure.

🌀 2. Weak or Reduced Airflow

If smoke, steam, or heat lingers longer than usual, your fan may be:

• Losing power
• Blocked with grease
• Running with worn belts
• Spinning in the wrong direction

Reduced airflow directly affects kitchen safety and NFPA 96 compliance.

🔥 3. Excessive Grease on the Fan Housing or Roof

Visible grease buildup on:

• The fan housing
• Hinges
• Duct connection
• Rooftop
  …means the fan is not effectively pulling grease through the filtration system.

This is a major fire hazard and will fail FDNY inspection.

⚠️ 4. Fan Not Turning On or Shutting Off Unexpectedly

This could indicate:

• Motor failure
• Blown fuses
• Electrical issues
• Faulty fan switch
• Broken belt

If your fan stops mid-operation, turn off cooking equipment immediately.

🌡️ 5. Hot Kitchen and Poor Ventilation

When your kitchen suddenly feels hotter or smoky, it means the fan isn’t exhausting heat properly.

This increases:

• HVAC load
• Fire risks
• Grease accumulation
• Staff discomfort

A properly functioning exhaust fan should keep your kitchen comfortable.

🧰 6. Burning Smell or Overheating

A burning smell usually means:

• Motor overheating
• Friction in bearings
• Electrical shorts
• Fan belt melting

Shut the fan down and call for service immediately.

🕒 7. Long Gaps Between Maintenance

Exhaust fans require routine service. If your fan hasn’t been inspected in:

• 3–6 months for busy kitchens
• 6–12 months for low-volume kitchens

…it may already be struggling.

Preventive maintenance avoids expensive repairs.

👨‍🔧 Why Exhaust Fan Service Is Critical

• Prevents grease fires
• Ensures smooth airflow
• Avoids breakdowns during peak hours
• Protects your roof from grease damage
• Helps pass FDNY & NFPA inspections
• Extends fan and motor lifespan

⭐ Final Word

Your exhaust fan is more than just a ventilation tool—it’s a critical safety device. If you notice any of these signs, schedule service immediately to keep your kitchen safe, compliant, and fully operational.