How to Clean Greasy Extractor Fan Filters
Sticky, yellow cooker hood filters come clean in a sink of hot water. Use Soda Crystals for stainless steel filters, or Castile Soap for aluminium ones.
Takes 30 minutes
What you’ll need
- Stainless steel filters: 2 tbsp Soda Crystals
- Aluminium filters: 2 tbsp Organic Castile Soap
- A sink or bowl of hot water
- Bamboo Pot Brush or soft brush
- Rubber gloves
Method
- Switch off the cooker hood and unclip the metal mesh filters. Check your manual to see whether they’re stainless steel or aluminium. If you’re not sure, treat them as aluminium.
- Fill the sink with hot water. Stir in 2 tbsp Soda Crystals for stainless steel filters, or 2 tbsp Organic Castile Soap for aluminium filters.
- Soak the filters for 20–30 minutes.
- Scrub gently with a Bamboo Pot Brush, working from both sides.
- Rinse in hot water, shake off and leave to dry completely before clipping back in.
Metal mesh filters in cooker hoods and extractor fans. Charcoal and carbon filters can’t be washed; replace those instead.
Extractor filters trap fine droplets of cooking fat, which turn sticky and yellow over time. Hot water softens the fat, and an alkaline soak breaks it down so it rinses away.
Soda Crystals are strongly alkaline, which is perfect for stainless steel but darkens aluminium. Castile Soap is gentler and safe on aluminium, it just needs a bit more brushing.
The science: Sodium carbonate (PubChem, NIH) →
Aluminium in Soda Crystals: Soda Crystals turn aluminium dark and dull. Use Castile Soap for aluminium filters.
Charcoal or carbon filters: They can’t be washed. Replace them as your manual suggests.
The motor or lights: Only soak the removable filters. Wipe the hood itself with a damp, soapy cloth.
Keep Soda Crystals sealed in a cool, dry place, and Castile Soap tightly closed, out of reach of children and pets.
Wear rubber gloves: hot water and Soda Crystals together can irritate skin.
Switch off the cooker hood at the wall before removing the filters.
B&M Pro-Tip 1:
Soak the filters every 1–2 months if you fry often. Light grease comes off in minutes; heavy, months-old grease may need a second soak.
B&M Pro-Tip 2:
Many stainless steel filters are dishwasher-safe, but never add Soda Crystals to a dishwasher. If your manual allows it, use your usual dishwasher detergent instead.
Quick questions
How do I know if my filter is aluminium?
Check the manual or the label on the filter. Aluminium filters are usually light and dull grey. If you’re not sure, use Castile Soap, which is safe for both.
Can I put the filters in the dishwasher?
Only if your manual says so, and never with Soda Crystals.
How often should I clean them?
Every 1–2 months, or as soon as they feel sticky.
Try this next: Oven Rack Soak →