How often should you clean a cooker hood's grease filter and replace its charcoal filter?

The short answer

There are two filters and they work differently. The metal grease filter is washed, and the figure we found from a manufacturer is once a month (Novy). The charcoal (carbon) filter, found only on hoods that recirculate air back into the kitchen, cannot be washed and is replaced: Bosch US and Electrolux Australia say every 3 to 4 months, while Bosch's Malta page says once or twice a year. The honest summary is that the interval depends on how much you cook, so your model's manual is the figure that applies to you.

The metal grease filter

This is the washable mesh or metal panel behind the grille. It catches grease before it reaches the motor and ducting.

• Interval. Novy says it is best to clean it once a month, and, for hoods with an electronic indicator, after 20 hours of cooking. Electrolux Australia says grease filters should be cleaned "every few weeks or months, depending on usage". Bosch's UK cleaning page gives no interval.
• Dishwasher. Bosch says some of its grease filters are dishwasher safe and tells you to confirm that in the user manual first. Novy says its filters are dishwasher safe.
• By hand. Bosch says to soak the filter in warm water with a mild detergent, scrub with a soft brush or sponge, rinse thoroughly and let it air dry. Novy says hot water with soda or detergent.

The charcoal filter

• It cannot be washed. Bosch US says carbon or charcoal filters used in ventilation cannot be cleaned, only replaced. Bosch UK says recirculating filters are designed for one-time use.
• Bosch US: replace every 3 to 4 months, depending on usage.
• Bosch Malta: depending on usage, usually enough to change it once or twice a year.
• Electrolux Australia: typically every 3 to 4 months. It lists lingering cooking odours and reduced airflow as signs that the filter is saturated, and says that how often you clean the grease filter also affects the timing.
• Long-life filters. Electrolux describes a long-life type that can be regenerated rather than replaced, and Bosch UK's page describes heating one in the oven for 120 minutes. Whether your hood takes one, and how many times it can be regenerated, is model-specific. Follow the manual.

If your hood vents outside through a duct, it normally has no charcoal filter at all. Check before buying a replacement.

Why the figures differ

The brands publish different numbers because they assume different cooking habits and different filter designs. Bosch's own pages disagree with each other between the US (3 to 4 months) and Malta (once or twice a year). Treat the shortest figure as a sensible starting point if you fry often, and let odours and weak extraction tell you to change it sooner.

Before you rely on this

These are figures from three manufacturers' support pages, not a legal requirement. Siemens, Pitsos and other brands are not covered, and the Beko page could not be read when this guide was written. Your manual is the figure that applies to you.

Track it in Epimeleia

Add the cooker hood as an item, attach the manual, and set two recurring reminders: a monthly grease-filter wash and, if your hood recirculates, a charcoal-filter replacement every three to four months unless your manual says otherwise.