How to Clean Extractor Filters Properly

Grease builds up on your extractor hood and then it starts looking dull, and can even smell stale and even dog hairs can stick to the grease (I saw one once that looked like it had a fur coat with half inch dog hair all over it). If you are wondering how to clean extractor filters without making a mess of the kitchen, the good news is that it is usually straightforward – as long as you use the right method for the type of filter you have.

A clean extractor filter does more than improve appearance. It helps your hood remove cooking odours more effectively, reduces greasy residue settling on cupboards and walls, and can support better airflow over the hob. Leave it too long, and that sticky layer becomes much tougher to shift.

How to clean extractor filters without damaging them

The first job is to identify what kind of filter sits inside your extractor. Most kitchen extractors have either metal mesh or paper filters that are designed to be cleaned and reused, and/or charcoal filters that are designed to be replaced. The wrong approach can waste time and, in some cases, ruin the filter altogether.

Metal grease filters are the most common in domestic kitchens. These are usually made from aluminium with a stainless steel rim. These trap airborne grease before it reaches the motor and ducting. They can cope well with regular washing, but harsh scrubbing or very aggressive chemicals can mark the finish and even dissolve them.

Charcoal filters are different. They are used in recirculating extractors and are there to absorb odours rather than collect grease alone. Most are not washable. If your extractor manual says the charcoal filter is disposable, trying to soak and scrub it will not restore it properly. It will need replacing instead. This can be expensive. Search online for your extractor and buy the correct cartridge for your extractor.

Paper filters should be replaced as soon as they start looking brown, or if the paper has grease indicators in it when the paper is brown and starts going red and blotchy. The red spots means the paper needs replacing. For me this is something lots of people miss, as they never look up at their extractors above their ovens. When we do our pre cleaning checks at OvenGleamers we often find a saturated filter paper in the extractor hood. These should be replaced because of the fire risk – especially if the extractor is above a gas hob. An accidental flame up from your cooking will ignited the saturated filter instantaneously. This a big issue with student accommodation and HMOs rented out to students.

Before you start

Switch the extractor off at the mains if possible and make sure the hob below is cool. Put an old towel over the hob to catch drips and protect the surface. Removing the filters is usually a simple release catch or clip system, but it helps to support the filter with one hand as you unfasten it because greasy filters can be slippery. These can be fiddly, but with care you can unclip them.

If the filter has not been cleaned in months, then they may be very greasy. That is normal. The key is to loosen the grease first rather than attack it straight away.

What you will need

For most reusable extractor filters, warm water, washing-up liquid, bicarbonate of soda, a non-scratch brush or sponge, and a sink or washing-up bowl are enough. A degreasing solution made for kitchen use can help with stubborn build-up, but it should be suitable for the filter material.

Avoid steel wool, sharp tools and bleach-based or other high alkaline products such as shop bought oven cleaning products unless the manufacturer specifically allows them as these can scratch, discolour or weaken parts of the filter, or dissolve it completely.

The simplest method for metal extractor filters

For me the first thing is to look at the metal gauze and run you ringer over it and see how dirty it is. If it fells just slimy and the filter still looks shiny with no staines – i.e not  black or brown – then this filter can be cleaned with just a spray of degreaser and wiped off.

If the filter is thick in grease and/or has dirt and grease in the centre of the gauze then this will need something stronger and a longer time to get it clean.  So start with a hot soak. Fill a sink or deep tray with very warm water, add a generous amount of washing-up liquid and a few tablespoons of bicarbonate of soda, then place the filters in the solution.

Leave them to soak for at least 15 to 20 minutes. For heavier grease, half an hour is better. The heat helps soften the residue, while the detergent starts breaking down the oily layer.

Once soaked, lift the filter out carefully and scrub it gently with a soft brush. An old washing-up brush is often ideal because it can get into the mesh without tearing it up. Work along the frame, corners and any thicker patches of grease. You should find that much of the grime comes away without much force.

Rinse thoroughly with clean hot water. This matters more than people think. Any detergent left behind can attract more residue or leave marks when the filter dries. Shake off excess water and leave the filter to dry fully before putting it back into the extractor. Use a stainless steel cleaner to make it shine.

Depending on how greasy it is, you may have to do this more than once. That is when you take the filter out of the tray and rinse it off it still may look dirty inside the gauze of the filter. So put it in again. You may have to do this a few times on very dirty extractor filters.

Can you put extractor filters in the dishwasher?

Sometimes, yes. Many metal filters are labelled dishwasher-safe, and this can be a convenient option for light to moderate grease. Place them upright where possible and run a hot cycle with your usual detergent.

That said, dishwashers are not always the best solution for heavily clogged filters. Grease can bake on over time, and one cycle may not be enough. Aluminium filters can also dull or discolour and even dissolve in some dishwashers, particularly on very hot settings. If appearance matters to you, hand washing is often the safer option.

How to deal with stubborn grease

As I said above some very dirty filters need a few dips as they have a thick amber coating that feels more like varnish than grease. In those cases, one soak may not be enough. Repeat the soaking process with fresh hot water and detergent rather than scrubbing harder straight away.

A paste made from bicarbonate of soda and a small amount of water can help on persistent areas around the frame. Apply it, leave it for a few minutes, then work it in gently with a soft brush. This gives you a little more cleaning power without the harshness of abrasive products.

If grease is still not shifting, it may be time for a stronger kitchen degreaser approved for the surface. Test it on a small area first. Not every product is suitable for every finish, and with premium appliances it pays to be cautious.

What about charcoal filters?

This is where many people come unstuck. If your extractor uses charcoal filters, check the appliance instructions before doing anything else. Most standard charcoal filters are replace-only items and should be changed every few months depending on how often you cook.

Some newer long-life charcoal filters can be cleaned or regenerated, but the method is very specific. It may involve washing by hand, using a dishwasher programme, or heating the filter in the oven for a set time to dry and reactivate it. Guessing is not worth the risk. Though I haven’t seen these. Most extractor hoods with carbon filter canisters inside have canisters that are designed to be taken out and replaced with a new one rather than cleaned manually a

If there is a lingering cooking smell even after cleaning the metal grease filters, the charcoal filter may be spent. Replacing it is often the only way to restore proper odour control.

How do you change paper filters?

To change a paper filter is relatively straight forward. It’s normally a case of moving two clips on either side of the extractor filter holder and then it falls down. You should be able to take off the filter holder from the extractor. Then you can take out the paper (it will have two metal rods to keep the paper in place) and replace it, it will need cutting to size and put back in place – remember if the paper has grease indicators to put the paper in so the lines face you – this means that the paper has to be saturated right through to show the saturation markers. To clean the rest of the holder use washing up liquid and a wet microfibre cloth. You can buy replacement filters from Screwfix or Argos at Sainsburys.

How often should extractor filters be cleaned?

It depends on how much cooking your kitchen sees. In a busy family home where frying, roasting and daily meal prep are standard, metal grease filters often need cleaning around once a month. In a lighter-use kitchen, every six to eight weeks may be enough.

If you have an Aga, range cooker or a cooking setup that sees regular high-heat use, filters can load up faster than expected. A quick look every few weeks helps. If the filter feels tacky, looks yellowed, or the extractor seems noisier than usual, it is time. I have only seen extractor hoods above newer AGAs that because of building regulations have them installed.

Charcoal filters generally follow a replacement schedule rather than a cleaning schedule. Again, frequency depends on use, but many need changing every three to six months.

Replace paper filters when they are brown or when the grease indicators start showing red.

Signs your extractor needs attention beyond the filter

Cleaning the filter can make a big difference, but it is not a cure-all. If the hood is still struggling after the filters have been cleaned or replaced, grease may have built up elsewhere. The extractor body, fan housing and surrounding surfaces can all collect residue over time.

You may also notice drips from the underside, persistent odours, reduced suction or a greasy film on nearby cabinets. Those signs suggest the whole extractor needs a deeper clean, not just the removable filter panel.

This is especially common in homes where the extractor has been cleaned on the outside but never properly dealt with inside. From the outside it can look acceptable. Inside, it can be a very different story.

When DIY is fine – and when it is worth calling in a specialist

For light routine maintenance, cleaning removable metal filters at home is perfectly manageable. It is a sensible job to keep on top of between deeper appliance cleans, and regular attention makes the task much easier each time.

Where DIY becomes less appealing is when the filters are heavily clogged, the extractor interior is coated in grease, or the appliance is part of a high-value kitchen setup you do not want to risk marking. Premium hoods, integrated extractors and cooker canopies above range cookers often need a more careful touch. And even though they appear to be made of enamel and should be easy to clean the finish is always a powder coated finish which isn’t easy to clean at all. Any scrubbing using incorrect scourers or the wrong product can mean damaging your expensive extractor hood.

That is also where specialist cleaning earns its place. A proper service tackles the built-up grease that ordinary wipe-downs miss and restores the extractor to a much higher standard. For busy households, it saves a dirty, awkward job and gives you visible results without filling the kitchen with harsh fumes.

At OvenGleamers, that kind of transformation is exactly the point. When an extractor has gone beyond a simple soak-and-scrub, a professional clean can bring it back to a condition that feels right for the rest of your kitchen.

A few mistakes worth avoiding

One of the biggest mistakes is putting wet filters straight back into the extractor. Moisture and electrics are never a good mix, and trapped damp can attract more grime. Let filters dry completely before refitting them. Make sure that now water or solution is left inside the gauze.

Another is using caustic oven cleaners on every part of the extractor without checking suitability. What works on one surface may stain or damage another. Extractors often combine metal, coatings, glass and plastic components, and each one may respond differently.

Finally, do not wait until performance drops off badly. Cleaning little and often is easier, quicker and far kinder to the appliance than trying to rescue months of heavy grease in one go.

A clean extractor filter will not turn kitchen maintenance into anyone’s favourite job, but it does make the whole space feel fresher, brighter and better cared for – and that is usually worth half an hour at the sink.

Not replacing any greasy filters can increase a risk of fire in your kitchen and especially leaving paper filters saturated with grease can increase this risk.