How to clean a cooker hood filter and when to replace it

You can clean a metal cooker hood grease filter by soaking it in a hot solution of water and washing-up liquid, brushing it and rinsing it, or by washing it on its own in the dishwasher at no more than 70 °C. A carbon (odour) filter is not cleaned but replaced, according to the manual or the saturation indicator. Manufacturers recommend cleaning grease filters regularly, because accumulated grease can catch fire.

The procedure is based on the manual for the Bosch DRC97AQ50 extractor hood and on the manufacturer's support pages. The type of filters, the way they are fixed and the interval differ between models, so open the manual for your own cooker hood before cleaning.

Which filter you have

• A grease filter is a metal grille or cassette (usually made of aluminium or stainless steel) directly below the intake opening. It traps grease from cooking vapours and can be washed repeatedly.
• A carbon or odour filter sits behind the grease filter and is found only in cooker hoods that do not vent air outside but clean it and return it to the kitchen (recirculation mode). According to the Bosch manual, you cannot do without an odour filter in this mode.

If you are not sure, remove the grease filter and look above it. A dark cassette or insert containing granules is the carbon filter.

How often to clean the filter

The Bosch manual recommends cleaning grease filters every two months and also warns that grease deposited in the filters can catch fire. Never use the cooker hood without its grease filters. If you often fry or pan-roast meat, the filter will clog faster and it is worth washing it more often.

Many cooker hoods have a filter saturation indicator. After cleaning the grease filter or replacing the odour filter, the indicator must be reset as described in the manual, otherwise it will keep lighting up.

Before cleaning: safety

1. Switch off the cooker hood and let it and the hob cool down. The manual notes that the appliance heats up during operation.
2. If you will also be cleaning the casing or the inside, unplug the appliance or switch off the circuit breaker, as the manual requires.
3. Use stable steps. Do not stand on the hob or the worktop, and do not lean over the hob.
4. Open the filter cover slowly and hold it, as on some models it swings after opening.
5. Take hold of the filter from below and remove it horizontally so that grease does not drip from it or fall onto the hob.
6. Clean the inside of the cooker hood carefully, as the parts inside may have sharp edges.

Cleaning the grease filter by hand

Hand washing is gentler on the surface of the filter and suits heavily clogged filters, which would soil the other dishes in the dishwasher.

1. Fill a sink or bath with hot water and washing-up liquid.
2. Immerse the filters and leave them to soak. For stubborn grease, the manual allows a special degreaser designed for cooker hood filters.
3. Scrub the filters with a soft brush, following the direction of the grille on grille filters.
4. Rinse them thoroughly with warm water.
5. Leave them to drain and dry, and only then put them back.

Do not bend the filters; the Bosch manual warns that they could be damaged.

Grease filter in the dishwasher

According to the Bosch support page on cleaning the extractor hood filter, metal grease filters can also be washed in the dishwasher, in a programme without other dishes. The cooker hood manual adds several conditions:

• place the filters in the dishwasher loosely so that they do not get jammed,
• do not wash heavily soiled filters together with dishes,
• set the temperature to no more than 70 °C,
• bear in mind that the filter may discolour slightly. According to the manufacturer, this does not affect its function.

An important warning concerns detergents. Both the cooker hood manual and the manual for the Bosch SBV6ZCX16E dishwasher warn that strongly corrosive alkaline or strongly acidic cleaning products, especially professional and industrial ones, can cause an explosion in combination with aluminium parts in the dishwasher. For aluminium filters, therefore, use only an ordinary dishwasher detergent, and do not put the filters in during the dishwasher's cleaning programme. How to clean the dishwasher after washing greasy filters is described in the article How to clean a dishwasher.

Carbon filter: replacement instead of cleaning

According to the Bosch support page on the carbon filter, an extractor hood carbon filter cannot be cleaned, and a filter that no longer works must be replaced.

The replacement interval differs between manufacturers and types, so follow the manual or the saturation indicator. Regenerable odour filters also exist. For these, the Bosch manual refers to the instructions supplied with the filter, because the procedure differs between types. If cooking smells stay in the kitchen longer than before, even when the cooker hood runs at a higher setting, check the condition of the odour filter.

Cooker hood casing and controls

The Bosch manual distinguishes between surfaces:

• Stainless steel: a sponge cloth and a hot solution of water and washing-up liquid, always in the direction of the grain. Finally, a stainless steel care product can be applied in a thin layer.
• Lacquered surfaces: a sponge cloth and a hot washing solution.
• Aluminium, plastic and glass: a soft cloth and glass cleaner.
• Controls: never with a wet cloth and never with stainless steel cleaner. Moisture can get into the electronics.

Finally, dry all surfaces with a soft cloth. Do not use aggressive or abrasive products, products with a high alcohol content, hard wire wool or rough sponges. The manual also prohibits steam cleaners and high-pressure cleaners.

The most common mistakes

• Cooking without a grease filter. The Bosch manual prohibits this; grease would build up directly inside the cooker hood and in the ducting.
• Cleaning a hot cooker hood. After cooking, the casing is warm and the grease in the filter is liquid, so it easily drips onto the hob.
• Wire wool and scouring powder. They can scratch both stainless steel and aluminium, and the Bosch manual does not permit hard wire wool or rough sponges. A soft brush and time to soak are enough for filters.
• Oven cleaner on an aluminium filter. Strongly alkaline products can damage aluminium. Use them only where they belong, and according to the label.
• Refitting a wet filter. Water would run down into the cooker hood. Leave the filter to drain and dry.
• Forgotten saturation indicator. Reset it after cleaning or replacement, otherwise you will stop noticing the warning.

After refitting the filters, close the cover slowly, check that the filters are held firmly in their fixings, and switch the cooker hood on briefly. If you hear rattling, the filter is not seated correctly.

Grease on the cabinets around the cooker hood

Grease that the cooker hood does not capture settles on the upper cabinets, tiles and the top edges of the worktop. The procedure is similar to that for the casing:

1. Wipe the cabinets with a cloth soaked in warm water and washing-up liquid and dry them immediately.
2. On a sticky film, leave the solution to work for a while; do not scrub dry.
3. Test a stronger degreaser first in a hidden spot and follow the kitchen manufacturer's instructions, especially for glossy, lacquered and veneered doors.
4. When working with cleaning products, ventilate, wear gloves and never mix products. Why is explained in the article on dangerous combinations of cleaning products.

The cooker hood and the oven are usually cleaned at the same time, because grease from baking ends up on both. You can find the procedure for the oven in the article How to clean an oven. If you want to have the kitchen, including the filters and cabinets, cleaned in one go, this is a typical part of deep cleaning.