Advice
How to clean extractor fan filters
East Cambs Oven Cleaning, Burwell, Cambridgeshire. Published 15 September 2026.
The short answer
How do you clean extractor fan filters? Take the metal ones out and soak them flat in the hottest water your tap gives, with washing up liquid, for twenty minutes. The dishwasher works too, on a low temperature and a short cycle if your manual allows it, though it can discolour aluminium mesh for good. A carbon filter is never cleaned, it is replaced.
First, which filter have you got?
Every hood has a metal mesh filter, and it is the one you can see from underneath: layers of fine aluminium or stainless mesh in a frame, held by a catch. That is the one that soaks, and it lasts for years if it is looked after. Having the hood done with the oven is £20, and the price list has the rest of it.
Some hoods have a second one behind it. If yours vents back into the room rather than out through a wall, there is a carbon filter in there absorbing the smells, and carbon cannot be washed. Once it is full it is replaced rather than cleaned, and how often that comes round depends on how much frying goes on, so the maker's guide is the one to go by. Washing one does nothing except make it wet.
How to clean extractor fan filters: the soak, step by step
Half an hour, most of which is the filters sitting in the sink while you do something else.
Turn it off at the wall first
Not the button on the hood, the switch on the wall or the isolator. You are about to put a hand near a fan, and lights inside a canopy get hot enough to burn.
Drop the filters out
Most have a sprung catch or a small handle on the underside. Push and let the filter hinge down rather than pulling it, because the frames bend and then they rattle for the rest of their life.
Soak them flat in the hottest water the tap gives
Washing up liquid, or a degreaser if the mesh is properly loaded, and give it twenty minutes rather than two. Grease inside a mesh does not come out with a wipe, it comes out when it lets go of the metal.
Rinse both faces and dry them properly
A wet filter refitted over a hob drips onto the pan below and streaks the canopy you just cleaned. Shake them, stand them on a towel, and leave them until they are dry to the touch.
Do the canopy while the filters are out
This is the part almost nobody does, and it is the part that smells. The grease trap above the filters and the inside of the canopy collect the same grease, and with the filters out you can reach both with a cloth.
The dishwasher, and what the makers actually say about it
It is the quickest way to do it, and the makers are more relaxed about it than most oven cleaners will tell you. AEG says to wash the filter “in the dishwasher at a low temperature and a short cycle”, and that grease filters “may discolour after cleaning. This doesn’t affect the performance of the filter.” NEFF says only that “some NEFF grease filters are dishwasher safe” and to check your own manual first. So: the discolouration is real and it does not come back off, and the people who built the filter call it cosmetic rather than damage.
Two things follow, and neither is what you will read elsewhere. Check your manual before the first time, because NEFF is saying plainly that not every filter is made for it. And if you do use it, use the low temperature and the short cycle AEG specifies rather than the cycle the plates go on.
We still put ours in the sink, and the reason is grease rather than damage. A dishwasher cycle is short and the filter is upright in a rack; twenty minutes lying flat in water as hot as the tap gives, with a degreaser in it, gives the grease inside the mesh longer to let go. It also leaves the aluminium the colour it started. Stainless steel mesh takes the dishwasher better than aluminium, and most people cannot tell which they have without looking at the frame.
How to tell when a filter is finished
Soak it, dry it, then hold it up to a window or a light. If daylight comes through the mesh evenly, it is clean and it will go on for years. If the middle is dark while the edges glow, the grease has set between the layers of mesh and no amount of soaking is getting it out. That filter is a part now, rather than a job, and a new mesh is a few pounds against a hood that pulls nothing and smells anyway.
It is the test we use on every hood we open, and it is the reason we will tell you a filter needs replacing rather than charging you to clean it again.
Or have it done with the oven: £20 for the hood, filters taken out and cleaned and the canopy done by hand, while we are already in the kitchen.
Get a priceWhat the sink cannot get to
Filters soaked and a cloth round the canopy is most of the job, and it is worth doing. These are the parts left after that. Ductwork inside the wall or the ceiling is a different trade with different equipment, and in a domestic kitchen it is rarely what is causing the smell.
- The grease trap on the hoods where it does not lift out, which is where the smell sits
- Inside the chimney section above the canopy, on a 90cm hood or an island one
- A carbon filter that is full, because it is replaced rather than cleaned and most people do not know theirs is there
- Knowing which of those three is causing the smell, which is the part that saves you buying the wrong thing
An extractor is £20 alongside an oven clean, or £30 for a hood 90cm or wider, with the filters taken out and cleaned, the trap and the canopy done by hand, and the carbon filter identified if there is one. Booked on its own a standard hood is £30 and a 90cm one £40, and the £70 minimum applies to a visit with no oven in it. The detail is on the extractor hood page, and whether paying somebody is worth it has the arithmetic for the kitchen as a whole.
Questions about extractor filters
Can I put extractor filters in the dishwasher?
You can, and an aluminium mesh one usually comes out chalky grey and stays that way. Dishwasher detergent is strongly alkaline and it attacks the aluminium itself rather than the grease on it. Stainless steel mesh survives it better, but a sink of hot water and washing up liquid gets more grease out of either of them and ruins neither.
How often do extractor filters need doing?
Hold one up to a light rather than looking at a calendar. If daylight comes through the mesh evenly, it is fine. If the middle has gone dark, the grease is sitting inside the layers and it is due. Somebody frying most nights will be looking at that every few weeks, and somebody who boils pasta twice a week will not.
Why does my extractor still smell after I have cleaned the filters?
Because the filter is the part you can reach and not the part that holds the smell. Grease collects in the trap above the filters and on the inside of the canopy, and a recirculating hood also has a carbon filter that absorbs odour until it is full, at which point it is replaced rather than cleaned.
Can I run the hood with the filters out?
Not for long. The metal filter is the only thing between your frying pan and the fan, so with it out the grease goes straight onto the impeller and into the duct, where nothing you own can reach it. If a filter is soaking, leave the extractor off until it is back in.
What does it cost to have the extractor done with everything else?
Done in the same visit as the oven it costs £20, or £30 for a hood 90cm or wider, which is how most people have it done because we are already in the kitchen with the oven in pieces. By itself it is £30, or £40 for the 90cm size, and a visit with no oven in it has the £70 minimum on it.
When to stop
Stop and hand it over when the mesh stays dark in the middle after a proper soak, because that filter is finished and wants replacing rather than cleaning, or when the grease trap and the inside of the canopy are the problem rather than the filters. Those are above head height, over a hob, and they are the part almost nobody does.
About East Cambs Oven Cleaning
Who we are and how we set our prices
We clean ovens, hobs, extractor hoods, range cookers, AGAs, microwaves and barbecues by hand, in the customer’s kitchen, across 31 towns and villages in East Cambridgeshire, Newmarket and west Suffolk from a base in Burwell, Cambridgeshire. A single oven is £75, the whole price list is published, and the price is fixed in writing before we set off.
Before setting those prices we read the published price lists of 11 oven cleaning businesses covering this patch, on 12 September 2026. 3 of them publish no price at all, and of the 25 pages ranking for oven cleaning across the county, 7 put a number on the page. How those figures were gathered, and when they were last checked.
Sources
Every outside claim on this page, with where it came from and the date it was read. Our own prices and the local price survey are published in full on the price list, with the log of when they were last checked.
See the sources
- How to clean the filters on your AEG cooker hoodAEG (UK support) · read 23 September 2026What the maker says about washing a metal grease filter in a dishwasher, which is the opposite of what this site said until 23 September 2026. AEG: "Wash the filter in the dishwasher at a low temperature and a short cycle", and "Grease filters may discolour after cleaning. This doesn't affect the performance of the filter." So the discolouration is real and permanent, and the maker calls it cosmetic.
- How to clean cooker hood filtersNEFF (UK) · read 23 September 2026That it depends on the filter: "Some NEFF grease filters are dishwasher safe. Check your user manual to confirm if your filter can be cleaned in the dishwasher", and "washing the filters in a dishwasher may result in slight discoloration". It also says to wash them on their own, and to avoid a hairdryer or direct heat for drying because that can damage them.
- Oven Pride, the manufacturer's own warnings and ingredientsOven Pride · read 23 September 2026What a caustic oven cleaner may and may not touch, from the label of the product this article names. It gives the contents as "5 - <12% Sodium Hydroxide" and the hazard as "May be corrosive to metals & Causes severe skin burns and eye damage". Its DO NOT list is the striking part: do not "use on aluminium, zinc, copper, tin, painted, damaged, self-cleaning or non-stick surfaces", and do not let it "come into contact with oven trim, hinges, glass oven door, door seals, pilot light or heating and fan elements". So the maker itself rules out most of the oven, including self-cleaning surfaces, which is what a catalytic liner is.
Filters cleaned, canopy done, £20 with an oven clean
Hood, filters and trap while the oven is being done, in one visit rather than three. East Cambridgeshire and west Suffolk from Burwell, Cambridgeshire, no VAT, and no travel charge inside 12 miles.
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