Your rangehood works hard and gets ignored. Every time you fry, grill or sear, it pulls a haze of vaporised fat up and through its filters, where the grease cools and collects. Over months that build-up clogs the airflow, leaves a sticky film on the kitchen, and quietly becomes a fire hazard sitting directly above your cooktop. The good news is that cleaning a rangehood filter is one of the easier maintenance jobs in the kitchen once you know how. This step-by-step guide covers aluminium mesh and baffle filters, when to replace carbon filters, and how to tell when the job is bigger than the filters alone.
Most rangehoods use one of two filter types. Aluminium mesh filters are thin, layered metal panels found in most domestic hoods. Baffle filters are heavier, slotted metal channels more common in larger or commercial-style hoods. Both trap grease and both can be cleaned by soaking, though they need slightly different handling.
How often should you clean a rangehood filter?
As a rule of thumb, clean your rangehood filters every four to six weeks if you cook most nights, and at least every two to three months for lighter use. If you fry or wok-cook regularly, lean towards the shorter end, because oily cooking loads the filters fastest.
There are obvious signs a clean is overdue. The filter feels tacky or looks discoloured, the fan seems louder or weaker, a greasy film starts settling on nearby surfaces, or cooking smells linger longer than they used to. A clogged filter cannot pull air properly, so a sluggish rangehood is usually a dirty one rather than a faulty one.
Letting filters go for many months is where the real risk creeps in, which is worth understanding before we get to the method.
Why a greasy filter is a genuine fire risk
A filter caked in cooled fat sits a short distance above open flames or hot elements. Grease is flammable, and a heavy build-up can ignite from a flare-up below, then carry flame up into the hood and ducting. Rangehood and exhaust grease is a recognised contributor to kitchen fires, which is exactly why commercial kitchens are required to clean their exhaust systems on a strict schedule.
Your home does not have those regulations, but the physics are the same. Keeping the filters clean is not just about airflow and tidiness, it genuinely lowers the fire risk in the busiest, hottest part of your kitchen. If you have noticed grease building up here, it is often a wider sign your cooking area needs attention, which we cover in our guide to the signs your oven needs cleaning.
Step by step: cleaning mesh and baffle filters
The core method is the same for both filter types. Work in order and give the soak enough time to do its job.
- 1Turn the rangehood off and, if it is hardwired with accessible lighting, switch the light off too. Let everything cool fully before you start.
- 2Release the filters. Mesh filters usually have a small spring-loaded clip or tab you push to drop the panel down. Baffle filters lift and slide out of their channel. Note which way they sit so they go back the same way.
- 3Boil a kettle and prepare a soak. In the sink or a large tub, combine very hot water, a good squirt of dishwashing liquid and a generous scoop of bicarbonate of soda. The bicarb cuts grease effectively without harsh chemicals.
- 4Submerge the filters fully and leave them to soak for fifteen to thirty minutes, longer if they are heavily clogged. The hot water and bicarb loosen the fat so you barely have to scrub.
- 5Scrub gently with a soft brush or non-metallic pad, working along the mesh layers or through the baffle slots. Avoid wire brushes on aluminium, as they scratch and damage the metal.
- 6Rinse thoroughly under hot water until the water runs clear and the filter no longer feels tacky.
- 7Dry completely before refitting. Stand the filters up or pat them dry, since refitting a wet filter can leave water marks and slows everything down.
- 8Refit in the original orientation and run the fan briefly to confirm airflow has returned.
A quick note on dishwashers. Many aluminium mesh filters can go through a dishwasher on a hot cycle, but it can dull or discolour the metal over time, and baffle filters are often too large. Hand-soaking is gentler and reliable.
Carbon filters are different: replace, do not wash
If your rangehood recirculates air back into the kitchen rather than venting outside, it likely has a carbon, or charcoal, filter as well as the grease filter. These absorb odours, and crucially they cannot be washed. Soaking a carbon filter destroys it.
Carbon filters are replaced, not cleaned, typically every three to six months depending on how much you cook. Check your model's manual for the right replacement part and interval. A saturated carbon filter stops removing smells, which is often why a recirculating rangehood seems to clear odours less well over time even when the metal filter is spotless.
What about the fan housing and ducting?
Cleaning the filters handles the part you can easily remove, but grease also coats the fan blades, the inside of the hood and the ducting beyond. Over years this internal build-up reduces performance and adds to the fire risk in a place you cannot reach with a soak.
If your rangehood still feels weak after a thorough filter clean, smells of old grease, or has years of neglect behind it, the housing and fan likely need attention too. That is genuinely fiddly and sometimes requires partial dismantling, which is where a professional clean earns its keep. We strip filters, degrease the housing and fan, and restore proper extraction as part of our rangehood cleaning service, and many customers book it alongside a full oven clean so the whole cooking zone is done at once.
Keep your kitchen safer and your air cleaner
Clean filters mean better extraction, less grease settling around your kitchen, and a meaningfully lower fire risk above your cooktop. A regular soak handles the filters, replacing the carbon filter on schedule keeps odours in check, and an occasional professional clean takes care of the fan, housing and ducting you simply cannot reach by hand. If your rangehood is overdue for a proper degrease, or you would rather have the whole job done in one visit, book a rangehood and oven clean online at fixed, GST-inclusive pricing with no call-out fee.