How to Clean a Cooker Hood and Grease Filter

A cooker hood gets dirty invisibly: grease settles in an even layer and goes unnoticed for years, until the airflow has halved. The real work here is not the housing but the metal filter, and it can almost always be cleaned without special chemicals if you know the proportion and the timing.

What you need

• Baking soda — 100 g
• Washing-up liquid — 2 tablespoons
• Citric acid — one sachet
• White vinegar 9 % — for the housing

• A large pot or basin the filter fits into
• An old toothbrush
• Microfibre cloth
• Rubber gloves

Time: 40 minutes of active work.

Step by step: the filter

1. Remove the filter. On most models it sits on clips and comes out without tools. Photograph its position so you do not refit it the wrong way round.
2. Boil water. Fill the basin so the filter is fully submerged.
3. Add the soda. 100 g of soda and 2 tablespoons of washing-up liquid per 5 litres, added in portions — the mix foams.
4. Leave for 20–30 minutes. The grease comes away by itself, in layers; the water darkens noticeably.
5. Work the mesh with a brush. Along the cells, without pressure — aluminium mesh deforms easily.
6. Dry it completely. A damp filter must not go back: moisture under grease produces a smell.

Method 2 — the dishwasher

A metal filter can go through a long dishwasher programme at 60–70 °C. It is the least laborious option with two limits: alkaline tablets darken aluminium (cosmetic, not functional), and a badly neglected filter will not come clean in one cycle. A carbon filter never goes in the dishwasher — it is disposable and replaced every three to six months.

Method 3 — housing and ducting

The housing washes with warm water and vinegar at one to three, using microfibre. Wipe stainless steel along the grain of the polish or it streaks. The area around the motor gets a damp wipe, never a soaking: there is wiring in there. Do not dismantle the ducting yourself — that is a ventilation engineer's job.

What to avoid

• Scouring powder on stainless steel. Scratches on a polished surface show under any light.
• Boiling water on a filter straight after cooking. The temperature shock deforms the thin mesh.
• Flooding the motor area. The most common reason a hood stops switching on after a “thorough” clean.
• Refitting a washed carbon filter. It does not recover; it is only replaced.

When a filter will no longer wash

Metal mesh lasts years, but not forever. If the cells stay blocked after a full soak and the mesh no longer passes light evenly, the grease has polymerised inside the weave and cannot be reached mechanically without deforming it. That is the moment to replace: a new filter costs less than the hour you would spend on hopeless scrubbing.

The second sign is a mesh crumbling at the edges or gone wavy. A deformed filter no longer seats tightly, and the grease goes straight past it into the motor.

Between cleans

• Switch the hood on a minute before you start cooking and leave it running for five to ten minutes after.
• Wipe the housing weekly with a damp cloth: fresh grease comes off with no product at all.
• Note the date the carbon filter was changed — in recirculation mode it works for three to six months.
• Do not cook on full heat with the hood off: that is exactly how the layer forms.

When to call a cleaner

If a filter has gone a year or more, the grease polymerises: soaking gives only partial results and the rest has to come off mechanically, at the risk of crushing the mesh. With us hood cleaning costs from UAH 350 — filter, housing outside and the reachable interior. It is usually taken with the oven and fridge as part of the kitchen: coming out for a single hood is not worth it for either side. Details on the hood cleaning page.

Frequently asked questions

How often should the grease filter be washed?

Every two months with daily cooking. The signs are reduced airflow and visible droplets on the mesh when tilted.

Can the filter go in the dishwasher?

A metal one can, on a long programme at 60–70 °C. A carbon filter never — it is a consumable.

Why is there a smell after cleaning?

Usually the filter was refitted damp. Dry it fully and check whether the carbon filter is due.

Photo credit

Grease Lock Filter — Clean & Dirty, GreaseLock, CC BY-SA 3.0