Bathroom extractor fan gone loud or vibrating: what it means

What the character of the noise tells you

A rhythmic ticking or clicking that speeds up with the fan usually means something loose is catching the impeller — a bit of grit, a hair clip, or dust that has built into a hard shell on one blade, throwing it off balance. A steady rattle that does not change with speed more often points to the housing itself, or a loose grille vibrating against the ceiling.

A high, continuous whine or grinding sound, especially one that gets worse over weeks, is the classic sign of a bearing wearing out in the motor. A low hum or buzz that you feel as much as hear, with the fan visibly shaking on its mount, usually means the unit has come loose from the ceiling or duct rather than anything being wrong with the motor.

Whistling or a hollow droning sound that changes when you open or close the bathroom door is rarely the fan at all — that points towards the duct or the vent outside, which is a different problem with a different fix.

What you can check yourself before doing anything

Turn the fan off at the switch, let it stop completely, and look at the grille from underneath with a torch. A thick grey felt of dust on the blades or housing is common in bathrooms that get a lot of use, and it is worth ruling out first since it is the easiest fix.

Gently wobble the grille or visible housing by hand — without forcing anything — to see if it moves independently of the ceiling. If the whole unit shifts, the mounting screws or the duct clip behind it have likely worked loose over time, which is common in panel-block bathrooms where the ceiling material is thin plasterboard.

Note whether the noise happens at switch-on, only at full speed, or continuously including a few minutes after switch-off if your fan has a timer or humidity sensor running it on. That timing is useful information if you end up describing the fault to someone else.

Cleaning that usually solves it

Isolate the fan at the switch or the consumer unit before touching it. Most bathroom extractor grilles either clip or unscrew — with the cover off, vacuum the blades and housing with a narrow nozzle attachment, then wipe them with a cloth dampened in warm water and a little washing-up liquid, avoiding the motor casing itself.

A soft brush, such as an old toothbrush, is useful for getting dust off individual blades without bending them, since a bent blade will throw the fan off balance again even after cleaning. Let everything dry fully before refitting the cover and switching the power back on.

This is a job most people can do themselves in twenty minutes with basic tools, and it resolves a large share of noise complaints that turn out to be dust rather than mechanical wear.

When the cause is the bearing or motor, not dust

If you have cleaned the fan and the whine, grinding, or hum persists, the bearing that the motor spindle turns on is likely worn. This happens gradually with age and with fans that run for long hours, and no amount of cleaning will quieten it, because the noise comes from metal-on-metal contact inside a sealed unit you cannot service by hand.

A worn bearing does not usually make a fan dangerous to keep running for a short while, but it will get louder and eventually the motor can seize or overheat. At that point replacement is the honest answer rather than repair, since extractor fan motors are not designed to be opened up and rebuilt.

Because the fan is on the mains electrical circuit, swapping the unit or checking the wiring behind it is electrical work — that is something we do from 49 € per hour, and it is worth having it looked at once you suspect the motor rather than waiting for it to fail completely.

When the ductwork is the culprit, not the fan itself

If the fan sounds fine on the bench, so to speak — smooth and quiet when you check it with the cover off — but the noise reappears once it is connected to the duct and running through the wall or ceiling, the duct itself is probably resonating. A loose flexible duct, a section that has sagged and kinked, or a badly fitted wall cap outside can all buzz or whistle at certain fan speeds.

This is more common in older buildings where the ducting was added later and run through a false ceiling or an external wall sleeve, and in Soviet-era panel blocks where the original shared ventilation shaft has been adapted for a modern fan. The fix is usually re-securing or replacing a length of duct rather than anything to do with the fan's electronics.

If you notice damp smells alongside the noise, or condensation forming inside the duct run, that is a separate but related issue covered in our guide on mould and ventilation, since a fan working against a poor duct run will also ventilate the room badly even when it is not making a sound.

• Rhythmic ticking that speeds up with the fan: check for debris caught on the blades
• Continuous whine or grinding that worsens over weeks: likely a worn bearing
• Low hum with visible shaking: mounting or duct clip has come loose
• Whistling that changes with the bathroom door: usually the duct, not the fan
• Noise gone after cleaning: dust was the cause
• Noise unchanged after cleaning: motor or bearing wear, plan for replacement
• Noise only present when connected to the duct: duct resonance or a loose fitting

When it is safe to wait and when it is not

A fan that is merely noisier than it used to be, with no burning smell, no smoke, and no tripping of the circuit, can usually wait a few weeks while you arrange a repair or replacement at a convenient time. Cleaning it in the meantime, as described above, often takes the edge off the noise even if it does not fully fix a mechanical fault.

Do not wait if you smell burning, hear the motor labouring and struggling to start, see the fan trip the circuit breaker, or notice the housing getting hot to the touch. Those are signs the motor is failing in a way that could damage the wiring behind it, and the fan should be switched off at the isolator until it is checked.

If you are not confident opening the unit yourself, or the noise persists after a clean and you suspect it needs replacing, that is straightforward hourly work for us — from 45 € per hour for the plumbing and ducting side, or from 49 € per hour where the fan needs disconnecting and rewiring by an electrician.