How to Clean and Replace Your Range Hood Grease Filters — Stop Recirculating Grease Through Your Kitchen

A greasy range hood filter stops capturing smoke and grease and starts dripping it back — here's how to degrease metal mesh filters, when to replace them, and how to handle charcoal filters on ductless hoods.

Turn on your range hood and hold a sheet of paper towel against the filter. If the hood pulls the towel in, air is moving — but that doesn’t mean the filter is working. A filter caked with cooking grease has almost no open mesh left, so smoke and grease particles blow around the hood cavity instead of being captured. Worse, that saturated grease layer is a fire fuel sitting directly above your cooktop, and on ductless hoods it can start dripping onto the stove below.

Cleaning the filters is the single most ignored kitchen maintenance task, and it’s one of the easiest: 15 minutes of work a few times a year, most of it hands-off soaking time.

Step 1: Identify Your Filter Type

Pull the filter out (most drop or swing out with a light tug — no tools) and look at it:

• Silver/gray metal mesh or baffles — a grease filter, designed to be washed and reused indefinitely. This is what most ducted hoods have.
• Dark, lightweight pad in a cardboard or thin plastic frame — a disposable grease pad. Don’t wash it; replace it.
• Chunky charcoal-filled cartridge — a carbon filter for ductless (recirculating) hoods. These can’t be washed; the activated charcoal inside is spent once saturated. Replace on schedule, typically every 3–6 months of regular cooking.

If you’re not sure whether your hood is ducted or recirculating, look for a duct leaving the top or back of the hood, or check above your kitchen cabinets — no duct anywhere means it’s recirculating, and you have charcoal filters in play.

Step 2: Degrease Metal Filters — the Boil-and-Soak Method

1. Fill a large pot or the sink with near-boiling water and add a heavy squirt of degreasing dish soap (the kind formulated for grease, not gentle formulas) plus 1/4 cup baking soda. Baking soda raises the alkalinity, which cuts hardened grease dramatically faster than soap alone.
2. Submerge the filters completely. Grease floats — weigh the filters down with a plate so they stay under.
3. Soak 20–30 minutes. You’ll watch the water turn cloudy brown as the grease releases.
4. Scrub with a stiff-bristle brush, working with the mesh, not against it. Pay attention to corners and the frame edges where grease pools.
5. Rinse with hot water and inspect against a light. You should see daylight through the mesh evenly. If some spots stay blocked, repeat the soak once.
6. Dry completely before reinstalling — a few hours air-drying or 10 minutes in a warm (not hot) oven after it’s been turned off.

Step 3: Know When a Metal Filter Is Done

Metal filters are durable, but they don’t last forever. Replace rather than re-clean when:

• The mesh is torn, warped, or no longer sits flat in the frame — gaps let grease-laden air bypass the filter entirely.
• Grease remains embedded after two full soak-and-scrub rounds.
• The frame coating is flaking into the mesh.

Replacement mesh filters run $10–$25 each and are sold by width — measure yours in inches (common sizes are 8.75 x 10.5 and similar) and match the mounting style (front tab, side tab, or slide-in). Buy by the old filter’s stamped dimensions, not the hood model number alone; most hoods take generic sizes.

Step 4: Handle Charcoal Filters Correctly

If your hood is ductless, the charcoal filter is doing the odor removal the metal filter can’t. Two rules:

• Replace, never wash. Water permanently ruins activated charcoal. Soaking it doesn’t refresh it — it kills it.
• Mark your calendar. Every 3–6 months for everyday cooking; every 2 months if you cook with oil at high heat often (stir-fries, frying). A stale, greasy kitchen smell despite the hood running is the tell that the charcoal is spent.

Many hoods let you run metal filters plus a charcoal filter behind them — the metal filter protects the charcoal and should still be cleaned on the schedule in Step 2.

How Often to Clean

• Light cooking (1–2 meals/day, little frying): every 3 months.
• Heavy or high-heat cooking, frequent frying: monthly.
• After any cooking fire flare-up or heavy smoke event: immediately.

A quick visual test tells you more than any schedule: hold the filter up to a light. If light doesn’t pass evenly through the mesh, it’s due.

Common Mistakes

• Running the hood with wet filters. Trapped moisture plus kitchen air gunks up the blower wheel — dry fully first.
• Scrubbing mesh aggressively against the holes. You’ll stretch the openings and create bypass gaps. Scrub along the mesh direction.
• Washing charcoal filters and reinstalling them — they’ll look fine and do nothing.
• Ignoring the hood housing. While the filters are out, wipe the cavity above them with degreaser on a sponge. That’s where the worst buildup hides.
• Cleaning filters and never checking the duct. If your hood is ducted and airflow still seems weak after clean filters, the duct or exterior cap may be blocked — that’s a separate problem.

When to Call a Pro

• The hood runs but barely moves air even with clean filters — could be a failed motor, stuck damper, or blocked duct inside the wall or ceiling.
• Grease has migrated into the blower housing or the motor makes grinding noises.
• The hood is hard-wired and you’re replacing the whole unit — hood circuits and duct connections are a job for an electrician, not a filter swap.
• You smell cooking odors in nearby rooms — the duct may be disconnected in the wall or attic, pumping grease-laden air into the structure.

An appliance or HVAC tech can diagnose airflow problems in under an hour; motor replacement typically runs $150–$350 installed.

Search intent for this topic clusters around “clean range hood filter,” “how to degrease range hood mesh filter,” “when to replace range hood filter,” and “can you wash charcoal range hood filters.” Lead with the boil-and-baking-soda soak method, the wash-vs-replace decision for each filter type, and cleaning frequency; secondary content should cover ductless vs ducted differences and filter sizing for replacements.

Typical homeowner queries: “range hood filter covered in grease won’t come clean,” “how often should I clean my range hood filter,” “can I put my range hood filter in the dishwasher,” “how do I know if my range hood is ductless,” and “why does my kitchen still smell with the hood on.”

Bottom Line

Pull the filters, soak them in near-boiling water with degreasing soap and baking soda for 20–30 minutes, scrub with the mesh, dry completely, reinstall. Metal filters last years with this routine; charcoal filters get replaced every 3–6 months, no exceptions. Ten minutes a quarter keeps grease out of your kitchen air — and out of the fire triangle above your stove.