How often should a cooker hood filter be cleaned?

Manufacturers typically specify monthly for a metal grease filter in normal domestic use, more often with heavy frying. Charcoal filters in recirculating hoods are replaced, not washed, usually every few months.

Can extractor filters go in the dishwasher?

Metal mesh filters usually can — check your manual, as a hot dishwasher cycle can discolour aluminium. Charcoal filters must never be washed; the charcoal is spent and needs replacing.

Is a greasy extractor really a fire risk?

Yes. Accumulated grease in the filter, canopy and duct sits directly above the hob and is combustible. Cooking is the leading cause of accidental house fires in the UK, and grease build-up is what lets a pan fire spread upward.

Why do the cupboards next to the hob get sticky?

Aerosolised fat from frying settles within a metre or two of the hob and, over months, oxidises into a sticky amber film that traps dust. A hood that is not extracting properly makes it worse, because more of that fat lands on the kitchen.

Caution

Updated 30 August 2026

Greasy Extractor Hood And Kitchen Cupboards

Sticky amber film on the cupboard doors above the hob, and an extractor filter you have never taken out.

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What's happening?

Frying and roasting put aerosolised fat into the air. Most of it lands within a couple of metres — on the cupboard doors either side of the hob, on the tiles, on the underside of wall units and on the ceiling above. What the extractor catches ends up in its metal mesh or grease filter, and that filter is a consumable most households have never removed. Once it is loaded, three things happen: the extraction drops off so more grease lands on the kitchen instead, the motor works harder, and the grease inside the hood and duct becomes a genuine fire load directly above an open flame or a hot hob. Cooking is the most common cause of accidental house fires in the UK, and a loaded hood is part of why one spreads.

What usually causes it?

Frying and roasting aerosolising fat that settles on nearby doors, tiles and unit undersides
A metal mesh grease filter never removed, washed or replaced
A charcoal filter in a recirculating hood left in far beyond its service life
Grease built up inside the hood canopy, impeller housing and duct where nobody looks
The hood not switched on early enough, or turned off immediately after cooking
Wiping only the door fronts, so the film on the unit undersides and ceiling keeps re-depositing
High-gloss, foil-wrapped or painted doors cleaned with abrasives, so the surface holds grease worse

Is it dangerous?

A heavily loaded extractor filter and greasy hood interior sit directly above the hob, and grease burns. Kitchen fires are the single most common cause of accidental dwelling fires in the UK, and a grease-laden canopy turns a pan fire into a spreading one. There is also a chemical risk: strong kitchen degreasers are caustic and permanently damage aluminium mesh filters, foil-wrapped doors and some painted finishes. Isolate the hood at the socket or the switch before removing filters — never work on it live.

Can I fix it myself?

Yes, and this is the maintenance job most worth doing. Switch the hood off at the socket or isolator, slide out the metal filter, and soak it in very hot water with washing-up liquid or run it through the dishwasher if the manual allows. Replace a charcoal filter rather than washing it — charcoal cannot be cleaned. Wipe the canopy, unit undersides and tiles with a warm degreaser suited to the finish. Do not use caustic oven cleaner on aluminium mesh or on foil-wrapped doors, and do not dismantle the motor or the ducting.

When should you call a cleaner?

Call a cleaner when the film has spread across the kitchen and up to the ceiling, when the doors are greasy enough to be sticky, or when a tenancy or sale inspection is coming — kitchen grease is one of the things inventories are most specific about. A deep clean covers what wiping does not: unit undersides, plinths, the tops of wall units, the hood interior and the tiling behind. Call an appliance engineer instead if the extractor has stopped drawing, has become noisy, or the lights and switches have failed.

What will the cleaner actually do?

Isolate the hood, remove the grease filters and degrease or replace them appropriately for the type
Clean the hood canopy, interior surfaces and accessible impeller housing rather than only the visible face
Degrease unit doors, handles, unit undersides, the tops of wall units, plinths and the ceiling above the hob
Clean the tiling, splashback and grout where the film sits, using a product safe for the finish
Clean the hob, pan supports, controls and the gap between hob and worktop where fat collects
Flag a dead extractor, a failed charcoal filter or a blocked duct as a repair or a replacement part

Frequently asked questions

We’re happy to answer all your questions.

Sources & References

Burnt-On Grease Inside The OvenCaution End Of Tenancy Clean And Deposit DisputesLow risk Dust Everywhere After Building WorkCaution

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