Ventilation · Kent
Kitchen extract fan not working or weak extraction
Weak extraction fills a kitchen with heat, steam and grease-laden air fast, and a dead fan can shut a service down under fire safety rules. Here is how to diagnose the fault before you call an engineer.
Quick answer
A kitchen extract fan not working or giving weak extraction is almost always down to grease build-up, a failed motor or belt, a tripped isolator, or ductwork blockage. Some causes are safe to check yourself, others need a qualified engineer with ventilation hygiene experience.
- Check the fan is receiving power and the isolator hasn't tripped.
- Look for grease saturation on filters, canopy and fan blades restricting airflow.
- Listen for unusual noise or vibration, which points to bearing or belt failure.
- Check whether the fan runs but extraction is still weak, suggesting a ducted blockage rather than a fan fault.
- Confirm nothing has damaged external ductwork, cowls or roof-mounted units.
If the fan is silent, sparking, or smells hot, stop using it and call an engineer rather than reset it repeatedly.
What to do before calling an engineer
A few checks can save a wasted call-out or help our engineers arrive with the right parts on the van.
- Check the isolator and fused spur. Roof and wall-mounted fans usually have a local isolator switch that can trip or be knocked off accidentally.
- Inspect and clean grease filters. Saturated filters starve the fan of airflow and are the single most common cause of weak extraction.
- Look at the canopy and duct entry. Grease deposits narrowing the duct throat reduce capacity even when the fan itself is fine.
- Check your last extract cleaning date. TR19 grease cleaning schedules exist for a reason: neglected ductwork chokes airflow gradually.
- Note when the problem started. Sudden failure points to electrical or mechanical fault; gradual weakening points to grease or duct build-up.
- Do not climb onto the roof. Roof-mounted fans sit near live electrics and edges. Leave access to a trained engineer.
⚠️When to call immediately
Some extraction faults are a fire and insurance risk, not just an inconvenience.
- The fan has stopped completely and cooking equipment, particularly gas appliances, is still in use.
- You smell burning, hear grinding or screeching, or see the motor casing discoloured.
- Smoke or heat visibly builds in the kitchen faster than usual.
- You cannot recall the last TR19 grease extract clean or have no certificate on file.
- An environmental health or fire officer has flagged extraction as a concern at a previous visit.
Get your extraction fixed properly
Advantage Catering Equipment covers Folkestone, Dover, Ashford and the wider Kent coast for extract fan repairs, motor and bearing replacement, and TR19 compliant grease extraction cleaning. Triple-ISO certified for quality, environmental and safety management.
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TR19 grease extract cleaning
Scheduled duct and canopy cleaning to keep airflow at design capacity and satisfy insurance requirements.
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Same-week engineer visits across Kent for fan, motor and canopy faults.
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Catch grease build-up and bearing wear before they cause a breakdown or a compliance failure.
Read more →Frequently asked questions
Why is my extract fan running but extraction still weak?
Usually grease build-up in the filters, canopy throat or ductwork restricting airflow, or a slipping belt reducing fan speed even though the motor turns. Both need physical inspection to confirm.
How often should extract ductwork be cleaned to prevent this?
TR19 guidance suggests frequency based on cooking type and hours, ranging from monthly for heavy fry operations to annually for light use kitchens. Neglected schedules are the most common root cause of gradual extraction loss.
Can I legally operate without working extraction?
No. Under fire safety and food hygiene regulations, adequate ventilation is required to control smoke, heat and grease-laden air. Continuing to cook with a failed fan can breach your insurance and fire risk assessment.
Is a noisy extract fan dangerous?
Grinding or screeching usually indicates bearing wear or a failing motor. Left unaddressed it can lead to complete fan failure, and in rare cases motor overheating poses a fire risk, so treat noise as an early warning.
Do you work on roof-mounted extract fans?
Yes, our engineers are trained and equipped for safe roof access and work on all common commercial extract fan types across Kent kitchens.
Don't let weak extraction shut your kitchen down
From tripped isolators to seized bearings and choked ductwork, Advantage Catering Equipment diagnoses and fixes extract fan faults across Folkestone and Kent, backed by ISO 9001, 14001 and 45001 certification.
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