Why Is My Extractor Fan Working But Not Extracting?

How Does an Extractor Fan Work?

An extractor fan pulls moisture, steam and odours from the room and moves them outside through a ventilation system.

The main parts involved are the motor, fan blades, ducting, vents and, on some models, a non-return valve. If one of these becomes blocked, damaged or faulty, airflow can be reduced even though the fan still appears to be running.

If the unit needs replacing rather than repairing, professional extractor fan replacement may be required.

Why Is My Extractor Fan Working But Not Extracting?

There are several possible reasons an extractor fan can run without extracting effectively.

Blocked Vents or Ducting

Blocked vents and ducting are common causes of poor airflow. Dust, debris, grease and other material can build up around the external vent or inside the ducting.

Signs of a blockage include:

• Debris around the external vent.
• Weak airflow when you test the fan.
• Increased condensation.
• Odours that remain after cooking or showering.

For wider guidance on extractor fan and cooker hood ventilation, see our cooker hood and extractor fan guide.

Dirty or Clogged Fan Blades

If your extractor fan is working but not extracting, dirty fan blades could be reducing its performance. Dust, grease and moisture can build up on the blades and fan cover.

Look for:

• Weak airflow.
• A stuffy bathroom or kitchen.
• Unusual fan noises.
• A greasy or sticky fan cover.
• Visible dust or dirt on the blades.

Motor Problems

Extractor fan motors can become worn over time. Moisture, grime, rust and general wear can affect the motor and reduce its performance.

Possible signs include:

• Rattling or grinding noises.
• The fan repeatedly switching on and off.
• The fan stopping completely.
• A burning smell while it is running.
• Rust or corrosion around the motor or fan components.
• Weak airflow despite the fan running.

A burning smell or obvious electrical fault should not be ignored. Switch off the power and arrange a professional inspection.

Faulty Non-Return Valve

A non-return valve helps prevent cold air, wind and draughts from entering through the ventilation system when the extractor fan is off.

If the valve becomes clogged with grease or debris, it can restrict airflow.

Signs can include:

• Cold draughts near the fan when it is switched off.
• An external vent flap that does not open properly.
• Reduced extraction despite clean fan blades.
• Grease or debris around the valve.

Incorrect Installation

Poor installation can affect how effectively an extractor fan moves air. This can be particularly relevant where the ventilation layout is difficult or the ducting has not been installed correctly.

Possible signs include:

• Weak airflow.
• Excessive noise when the fan is running.
• Lingering moisture or odours.
• Gaps or poor sealing around the ducting.
• Problems with the external venting.
• Condensation within the ducting.

If the problem has been present since the fan was installed, the installation and ventilation setup should be checked.

Damaged Extractor Ducting

Damaged ducting can allow air to escape before it reaches the external vent. Loose connections, crushed flexible ducting, holes and tears can all reduce extraction.

Check for:

• Visible gaps or loose connections.
• Kinked or compressed flexible ducting.
• Water stains near ducting.
• Weak airflow despite clean fan components.

How to Troubleshoot an Extractor Fan

Carry Out Basic Safety Checks

Before carrying out any checks or cleaning:

• Turn off the power at the main consumer unit.
• Wear protective gloves when handling the fan or surrounding components.
• Use a stable ladder if you need to reach a high fan.
• Make sure the work area is well lit.
• Keep tools and loose items clear of the working area.

Do not attempt electrical repairs unless you are suitably qualified to do so.

Test the Airflow

A simple airflow check can help confirm whether the fan is actually extracting air.

Turn the fan on and hold a small piece of toilet paper near the intake. If the fan is extracting properly, the paper should be drawn towards the intake.

You can also use a smoke pen or incense stick to observe the direction of airflow. For a more precise check, an anemometer can be used to measure airflow.

If the fan still has weak airflow after cleaning, check the external vent and accessible ducting for blockages.

Clean the Fan and External Vent

Start by checking the external vent and removing accessible debris. Make sure the vent flap can open and close properly.

Clean accessible areas around the fan blades and cover to remove dust and grease. Regular cleaning can help prevent buildup from restricting airflow.

After cleaning, switch the fan back on and test the airflow again.

Check the Ducting

Inspect accessible ducting for blockages, damage, loose connections or obvious kinks.

Do not dismantle inaccessible sections simply to investigate a blockage. If the ducting cannot be safely checked or the airflow remains poor, a professional inspection may be needed.

Reset the Extractor Fan

Some modern extractor fans with timers or electronic controls may need resetting.

If your model has a reset procedure, follow the manufacturer's instructions. You can also check the timer and speed settings to make sure they have not been changed.

For more complex models, refer to the user manual or contact a qualified professional.

How to Maintain Your Extractor Fan

Regular maintenance can help keep airflow working effectively.

• Check and clean the external vent regularly.
• Remove visible dust and buildup from accessible fan components.
• Check the fan periodically for unusual noises or vibrations.
• Check the timer settings if your fan has them.
• Inspect accessible ducting for obvious blockages or damage.
• Keep a note of recurring problems and cleaning dates.

If the fan continues to run without extracting after cleaning and basic checks, the problem may require professional attention.

When to Get Professional Extractor Fan Help

Some extractor fan problems cannot be resolved with cleaning or basic checks. Persistent weak airflow, damaged ducting, motor problems or installation issues may need professional inspection.

For London homeowners dealing with an ongoing extractor fan problem, Serviceteam can assess the issue and repair or replace the extractor fan where required.

If the extractor fan needs replacing rather than repairing, our appliance installation services in London can help with the installation.

Frequently Asked Questions - (FAQs)

What should I do if my extractor fan is not working properly?

Start by checking for visible blockages and cleaning accessible fan components. Check that the external vent is clear and test the airflow. If the problem continues, a professional inspection may be needed.

Why is my extractor fan not extracting?

Common causes include blocked vents or ducting, dirty fan blades, motor problems, a faulty non-return valve, damaged ducting or incorrect installation.

Why do extractor fans stop working?

Extractor fans can stop working because of motor problems, electrical faults, blockages or general wear. If the fan has stopped completely, the cause should be checked before attempting repairs.

Why is there no suction on my extractor fan?

Weak suction can be caused by dirty fan blades, blocked vents, restricted ducting, a faulty non-return valve or a worn motor.

How do I reset an extractor fan?

Some extractor fans have a reset procedure or electronic controls. Check the manufacturer's instructions for your model and review the timer or speed settings. If the fan still does not extract properly, professional help may be required.

Need help with an extractor fan that is running but not extracting? Serviceteam can inspect the problem and repair or replace the fan where required. Contact us to arrange an appointment.