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Kitchen extraction cleaning - fan noise
If your extraction has grown noisier over time - a louder hum, a rattle, a strained note - it is usually telling you something. Most often, the fan is straining because grease has loaded and unbalanced it, so it works harder and runs louder. Rising noise is an early warning worth heeding. Here is what a louder extraction is telling you, and what to do. This is general guidance.
The short answer
You mightn't notice it day to day, but if you stop and listen, your extraction may be running louder than it once did - a heavier hum, a rattle, a strained note. That change in sound is usually meaningful. Here's what a louder extraction is telling you. This is general guidance. Rising noise usually means strain. A gradual increase in your extraction's noise usually means the fan is straining - working harder than it should. A fan running freely and in good balance runs relatively quietly; a fan under strain (working hard, out of balance, or worn) runs louder. So when the extraction gets noisier over time, it's usually a sign the fan is under increasing strain. And the most common cause of that strain is grease. Grease loads and unbalances the fan. Here's the main mechanism. As grease builds up on the fan blades and housing, it does two things: Loads the fan. The grease adds weight, so the fan has to work harder to turn - straining the motor, which runs louder. Unbalances the fan. The grease builds up unevenly on the blades, throwing the fan out of balance - so it vibrates and runs rough, adding noise (a rattle, a vibration, a wobble). So a grease-laden fan is both harder-working and out of balance, which makes it noisier. And the wider system adds to it: grease building up in the filters and ductwork raises the airflow resistance, so the fan strains harder against a more choked system - adding to the effort and noise. So a louder extraction usually points to a grease-laden, straining fan and system (as covered in the a-louder-extractor-fan and when-extraction-gets-noisier-but-weaker pages). The noise is an early warning. This is why rising noise is worth heeding: it's an early warning. The increased noise tells you the fan is under strain (from grease) before it fails - so it's a prompt to act while the problem is still just strain and noise, not yet a breakdown. A fan straining under grease is on a path toward wear and failure (the strain wears the bearings and motor over time); the noise is the audible early sign of that. So a louder extraction is the fan flagging, early, that it needs attention. Other possible causes. Grease-driven strain is the commonest cause, but not the only one. Other possibilities: a worn or failing fan (worn bearings, a failing motor - which grease strain accelerates); a loose or damaged component (a loose fan, guard, or mounting rattling); or a drive-belt issue (a worn or misaligned belt). So while grease is the usual culprit (especially if the noise has crept up as the system got greasier), the fan itself may be worn or have a mechanical issue - which an inspection would find. What to do. The response to a louder extraction is to get it cleaned and checked. Cleaned: a proper extraction clean removes the grease that's loading and unbalancing the fan - restoring its balance and quietening it (a clean, balanced fan runs quieter). Checked: while cleaning, the fan's condition is checked - in case the strain has worn it (bearings, motor) or there's a mechanical issue needing attention. So cleaning usually restores the balance and quiet, and the check catches any wear the strain has caused (before it becomes a breakdown). So don't ignore a louder extraction. The takeaway. So a louder extraction usually means the fan is straining - most often because grease has loaded and unbalanced it (and choked the system) - and rising noise is an early warning worth heeding. Get the extraction cleaned (to restore the balance and quiet) and checked (in case the fan is worn). So listen to the noise - it's the fan telling you it's straining. This is general guidance.
Key points
Rising noise means strain
A gradual increase in your extraction's noise usually means the fan is straining - working harder than it should. A fan running freely and in good balance runs relatively quietly; a fan under strain (working hard, out of balance, or worn) runs louder. So when the extraction gets noisier over time - a heavier hum, a rattle, a strained note - it's usually a sign the fan is under increasing strain.
This makes the noise a meaningful signal, not just an annoyance. The change in sound reflects a change in how the fan is running: from quiet and easy to loud and strained. So rising noise is worth paying attention to, because it's telling you the fan's working condition has changed for the worse. The most common cause of that strain is grease (covered next) - so a louder extraction is often the audible sign of a grease-laden, straining system. So rising noise means strain - a straining fan runs louder - is the starting point: the increased noise signals a fan working harder than it should, which has a cause worth finding. So a noisier extraction usually signals a straining fan. This is general guidance.
Grease loads and unbalances
The most common cause of a fan straining and getting louder is grease. As grease builds up on the fan blades and housing, it does two things that make the fan noisier. It loads the fan: the grease adds weight, so the fan has to work harder to turn - straining the motor, which runs louder (a heavier, more laboured hum). And it unbalances the fan: the grease builds up unevenly on the blades, throwing the fan out of balance - so it vibrates and runs rough, adding noise (a rattle, a vibration, a wobble in the sound).
So a grease-laden fan is both harder-working (loaded) and out of balance (uneven grease) - which makes it noisier on both counts. And the wider system adds to it: grease building up in the filters and ductwork raises the airflow resistance, so the fan strains harder against a more choked system - adding to the effort and noise. So a louder extraction usually points to a grease-laden, straining fan and system (as covered in the a-louder-extractor-fan-what-its-telling-you page). This is why noise and grease go together: the grease that builds up in a neglected system is exactly what loads, unbalances and strains the fan into running louder. So grease loads and unbalances - harder-working and out of balance - is the main mechanism behind a louder extraction: grease making the fan strain and vibrate. So grease is usually why the fan has got louder. This is general guidance.
The noise is a warning
This is why rising noise is worth heeding: it's an early warning. The increased noise tells you the fan is under strain (from grease) before it fails - so it's a prompt to act while the problem is still just strain and noise, not yet a breakdown. A fan straining under grease is on a path toward wear and failure (the strain and imbalance wear the bearings and motor over time); the noise is the audible early sign of that path.
So a louder extraction is the fan flagging, early, that it needs attention - a chance to act before the strain turns into damage or a breakdown. If you heed it (clean and check the system), you address the grease strain while it's still recoverable, and catch any developing wear early. If you ignore it (dismiss the noise as just 'getting old'), the fan keeps straining, the wear accumulates, and it heads toward a breakdown (a seized or failed fan, stopping the extraction, as covered in the cost-of-an-extract-fan-seized-by-grease page). So the noise is a useful early warning precisely because it comes before the failure. So the noise is a warning - an early sign before a breakdown - is the key point: rising noise is the system's early alert, worth acting on rather than tuning out. So heed the noise as an early warning of strain. This is general guidance.
Other possible causes
Grease-driven strain is the commonest cause of a louder extraction, but not the only one. Other possibilities to consider: a worn or failing fan - worn bearings (which get noisier as they wear) or a failing motor, often the result of the fan being strained over time (grease strain accelerates this wear, so grease and wear are linked). A loose or damaged component - a loose fan, guard, mounting or fitting rattling or vibrating, which can develop as things work loose. A drive-belt issue - a worn, slipping, or misaligned drive belt (on a belt-driven fan) making noise.
So while grease is the usual culprit - especially if the noise has crept up gradually as the system got greasier - the fan itself may be worn (bearings, motor) or have a mechanical issue (a loose part, a belt) that's making the noise. These often go together with grease (the grease strain having worn the fan or worked things loose). An inspection distinguishes them: whether the noise is grease loading/imbalance (cleaned away), worn bearings (needing repair/replacement), or a mechanical issue (needing fixing). So other possible causes - wear, a loose part, or a belt - mean a louder extraction isn't always purely grease; the fan may be worn or have a fault, which cleaning alone won't fix. This is why checking the fan (not just cleaning) matters (covered next). So consider fan wear and mechanical issues alongside grease. This is general guidance.
Clean it and check it
The response to a louder extraction is to get it cleaned and checked. Cleaned: a proper extraction clean removes the grease that's loading and unbalancing the fan (and choking the system) - restoring the fan's balance and quietening it (a clean, balanced fan, in an unchoked system, runs quieter). So cleaning usually addresses the commonest cause and quietens the fan. Checked: while cleaning, the fan's condition is checked - in case the strain has worn it (bearings, motor) or there's a mechanical issue (a loose part, a belt) needing attention.
So the two together - clean and check - address a louder extraction properly: the clean removes the grease strain (the usual cause) and restores the quiet, and the check catches any wear the strain has caused or any mechanical issue, before it becomes a breakdown. If the noise is grease, cleaning fixes it; if the fan has been worn by the strain, the check identifies it so it can be repaired before it fails. So don't ignore a louder extraction, and don't just tolerate the noise: get the system cleaned (to restore the balance and quiet) and the fan checked (in case it's worn). This heeds the early warning the noise represents. So clean it and check it - restore the balance, catch any wear - is the takeaway: a louder extraction is the fan telling you it's straining, so clean the grease away and check the fan, catching the strain before it becomes a failure. So act on the noise: clean the system and check the fan. This is general guidance.
Questions
Usually because the fan is straining - grease building up on it loads and unbalances it, so it works harder and vibrates, running louder; grease in the wider system also raises resistance, adding to the strain and noise. A gradually louder extraction usually means the fan is straining, most often because of grease. As grease builds up on the fan blades and housing, it loads the fan (adding weight, so it works harder and the motor runs louder) and unbalances it (building up unevenly on the blades, so the fan vibrates and runs rough - a rattle or wobble). So a grease-laden fan is both harder-working and out of balance, making it noisier. And grease building up in the filters and ductwork raises the airflow resistance, so the fan strains harder against a more choked system, adding to the effort and noise. So a louder extraction usually points to a grease-laden, straining fan and system. Other causes (worn bearings, a loose part, a belt issue) are possible, but grease-driven strain is the commonest - especially if the noise has crept up as the system got greasier. So the answer is usually a grease-laden, straining fan. So usually grease loading and unbalancing the fan. This is general guidance.
It's worth acting on - rising noise is an early warning that the fan is straining (usually from grease), on a path toward wear and breakdown if left; heeding it lets you clean and check the system before a failure. A noisy extraction is worth acting on - not to panic over, but not to ignore either. Rising noise is an early warning: it tells you the fan is under strain (usually from grease loading and unbalancing it) before it fails. A fan straining under grease is on a path toward wear and breakdown (the strain and imbalance wear the bearings and motor over time), and the noise is the audible early sign of that path. So the noise gives you a chance to act while the problem is still just strain and noise, not yet a breakdown. If you heed it (clean and check the system), you address the grease strain and catch any developing wear early. If you ignore it, the fan keeps straining and heads toward a failure (a seized or failed fan, stopping the extraction). So a noisy extraction is a useful early warning worth heeding - act on it (clean and check) rather than tuning it out. So yes, worth acting on - it's an early warning. So worth heeding, not ignoring. This is general guidance.
Usually yes, if the noise is from grease - cleaning removes the grease loading and unbalancing the fan (and choking the system), restoring its balance so it runs quieter; if the fan has been worn by the strain, it may also need a repair. Usually yes - if the noise is from grease (the commonest cause), cleaning quietens the extraction. A proper extraction clean removes the grease that's loading and unbalancing the fan, and choking the wider system - so the fan is no longer straining under the extra weight, running out of balance, or fighting a choked system. A clean, balanced fan in an unchoked system runs quieter. So cleaning usually addresses the grease-driven noise and restores the quiet. The caveat is that if the fan has already been worn by the strain (worn bearings, a failing motor) or has a mechanical issue (a loose part, a belt), cleaning removes the grease but the fan itself may need a repair to fully resolve the noise - which is why checking the fan (as well as cleaning) matters. So cleaning quietens a grease-driven noise; a worn fan may also need attention. So usually yes for grease noise; check the fan too. So yes, if it's grease - and check for wear. This is general guidance.
Then the noise may be from fan wear (worn bearings, a failing motor) or a mechanical issue (a loose part, a belt) rather than grease - which needs the fan inspected and repaired, so have it checked as well as cleaned. If cleaning doesn't quieten the fan, the noise is probably not (or not only) from grease, but from the fan itself - fan wear or a mechanical issue. Possibilities: worn bearings (which get noisier as they wear), a failing motor, a loose or damaged component (a loose fan, guard or mounting rattling), or a drive-belt issue (worn, slipping or misaligned). These often result from the fan having been strained by grease over time (grease strain accelerates wear), so grease and wear can go together - but once the fan is worn or has a mechanical fault, cleaning the grease won't fully fix the noise; the fan needs inspecting and repairing. So if a clean doesn't quieten it, have the fan checked properly (its bearings, motor, mountings, belt) to identify and fix the mechanical cause. This is why the response to a louder extraction is to clean and check (not just clean) - so any wear or fault is caught. So it's likely fan wear or a mechanical issue - have it inspected and repaired. So then get the fan checked and repaired. This is general guidance.
Yes - if the strain causing the noise (usually grease) is left, the fan keeps working hard and out of balance, wearing the bearings and motor until it fails; heeding the noise and cleaning/checking the system catches it first. Yes - a louder fan can lead to a breakdown if the underlying strain is left unaddressed. The noise usually signals the fan straining under grease (loaded and unbalanced), and a fan running strained and out of balance wears over time - the strain and vibration wearing the bearings and motor - until it fails (a seized or failed fan that stops the extraction, as covered in the cost-of-an-extract-fan-seized-by-grease page). So the noise is an early point on a path toward a breakdown: strain and noise now, wear building, breakdown later if nothing changes. This is exactly why the noise is a valuable early warning - heeding it (cleaning the grease away to remove the strain, and checking the fan for any wear already caused) catches the problem before it becomes a breakdown. Ignoring it lets the strain continue toward failure. So a louder fan can lead to a breakdown if ignored - which is why you act on the noise. So yes, if the strain is left - so heed the warning. So yes; so clean and check it. This is general guidance.
Get it checked, not tune it out - the noise is an early warning of a straining, usually grease-laden fan; get the extraction cleaned and the fan checked, so you address the cause and catch any wear before a breakdown. Get the extraction cleaned and checked, rather than just getting used to (tuning out) the noise. The noise isn't something to simply tolerate or accept as the fan 'getting old' - it's an early warning that the fan is straining (usually from grease loading and unbalancing it), on a path toward wear and breakdown if left. So the right response is to act on it: get the system cleaned (removing the grease that's straining and unbalancing the fan, restoring its balance and quiet) and the fan checked (in case the strain has worn it or there's a mechanical issue needing repair). Tuning out the noise means ignoring the warning and letting the strain continue toward a failure. Acting on it means addressing the cause while it's still recoverable and catching any wear early. So don't just live with a louder extraction - have it cleaned and checked, heeding the early warning the noise gives. So get it checked and cleaned, not tune it out. So act on it, don't ignore it. This is general guidance.
A louder extraction usually means a grease-laden, straining fan; we clean the whole system to TR19 Grease - removing the grease loading and unbalancing the fan - and check its condition, restoring the balance and quiet and catching any wear early. Ask us to clean and check your noisy extraction. This is general guidance.
