Greasy Extractor Hood And Kitchen Cupboards

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

Who fixes this

• One-off deep clean
• Oven cleaning

Questions people ask

Sources & References

1. London Fire Brigade: Cooking safety
2. London Fire Brigade: White goods
3. HSE: Cleaning industry