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FIXED APPLIANCES & DEDICATED CIRCUITS

Extractor Fan Not Working

An extractor fan may stop working because of a failed isolator, blown fuse, stuck timer, humidity-sensor fault, blocked impeller, failed motor or missing permanent or switched supply.

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Stop if there is heat, burning, arcing, exposed parts or water near electrical equipment

Fixed appliances can draw high current and may remain connected even when their controls appear off. Do not remove covers or test exposed conductors. Leave affected circuits isolated and call a registered electrician or qualified appliance engineer where fixed wiring or internal faults are suspected.

MOST LIKELY CAUSES

Start with these

Isolator or fused spur off The fan may have lost its local supply.
Blocked or seized fan Dust and grease can stop the impeller.
Timer or sensor fault Electronic controls may fail while the motor is healthy.
Motor failure The fan can hum, start slowly or stop completely.
◫ Symptom variations Match the exact behaviour before testing. ⌄
  • Fan is completely dead
  • Fan hums but does not turn
  • Fan only works with light on
  • Fan runs constantly
  • Timer overrun no longer works
✓ Quick checks Safe checks using controls and front-panel devices only. ⌄
  1. Check the appliance control panel, timer, thermostat and child-lock settings.
  2. Confirm the local isolator or fused spur is on and undamaged.
  3. Inspect the consumer unit for a tripped breaker, RCBO or RCD.
  4. Look for heat, smell, moisture, buzzing or discolouration.
  5. Attempt one controlled reset only if no danger signs are present.
If operation returns: monitor the appliance and circuit closely.
If the fault remains: leave the appliance or dedicated circuit off and arrange testing.
1 Fix 1 — Check the local isolator and spur Follow this check without opening live or fixed electrical equipment. ⌄

Process

Confirm accessible controls are on and undamaged.

Success looks like: The fan resumes normal operation.
Failure means: If not, continue with control checks.
2 Fix 2 — Clean accessible grilles and vents Follow this check without opening live or fixed electrical equipment. ⌄

Process

With the fan isolated, remove surface dust and blockage only.

Success looks like: Airflow and fan operation improve.
Failure means: A seized or internal fault needs repair.
3 Fix 3 — Check timer and humidity settings Follow this check without opening live or fixed electrical equipment. ⌄

Process

Review user controls and allow for overrun delays.

Success looks like: Normal automatic operation returns.
Failure means: If not, the sensor, timer or supply may be faulty.
⌁ Common causes explained Why the appliance or circuit may fail. ⌄

An extractor fan may stop working because of a failed isolator, blown fuse, stuck timer, humidity-sensor fault, blocked impeller, failed motor or missing permanent or switched supply.

Fixed appliances often use dedicated circuits, high-current isolators, fused spurs or local controls. The fault may be in the appliance, the control accessory, the cable or the circuit protection.

⌘ Advanced diagnostics Technician-level testing for a competent electrician. ⌄
  • Verify permanent live, switched live and neutral.
  • Test timer and humidity-sensor output.
  • Inspect motor and capacitor where fitted.
  • Check duct blockage and backdraught shutter.
  • Test insulation resistance and local isolation.
▣ Parts that may need replacing Common components linked to this fault. ⌄
  • Fan motor
  • Complete extractor fan
  • Timer module
  • Humidity sensor
  • Fan isolator
  • Fused spur or fuse
  • Capacitor where fitted
! When to call an electrician or appliance engineer Conditions that should end DIY troubleshooting. ⌄
  • The appliance or isolator is hot, burnt, buzzing or crackling.
  • The breaker, RCBO, RCD or fused spur operates repeatedly.
  • Water may have reached electrical components.
  • The appliance is permanently wired or high current.
  • The fault remains after simple control and supply checks.
  • Internal covers or fixed wiring would need to be opened.
? Frequently asked questions Common questions about fixed appliances. ⌄

Can the appliance be faulty even when the breaker stays on?

Yes. Controls, elements, motors and internal connections can fail without operating circuit protection.

Should I repeatedly reset a dedicated circuit?

No. One controlled reset is enough to confirm whether the fault remains.

Can I fit a larger fuse or breaker?

No. Protection must match the cable and appliance design. Increasing it can create a fire risk.