If your range hood has gone quiet and the metal mesh above the burners looks like a tinted screen, that buildup is animal fat, plant oils, and aerosolized starch that has cooked onto aluminum. How to clean stove vent filter grease comes down to alkaline chemistry: hot water, sodium carbonate, and a little time. Skip the wire brush and the oven cleaner. The right method takes 15 to 30 minutes of unattended soak, costs under three dollars per cycle, and restores 95 percent of the airflow your hood lost.
Why Filters Get So Clogged
A range hood pulls 250 to 600 cubic feet per minute past the filter every time you saute, sear, or fry. Vaporized fat condenses on the cool aluminum and oxidizes into a varnish-like film. Manufacturers including Broan, GE, Whirlpool, and Vent-A-Hood recommend cleaning every 30 days for heavy cooks, every 60 to 90 days for light cooks. Wait longer than six months and the grease polymerizes, which is when boiling-water tricks stop working and you need ammonia or a dedicated degreaser.
Method 1: Boiling Water and Baking Soda
This is the routine cleanup that handles 60 to 90 days of normal grease. Cheap, safe for aluminum, no fumes.
- Fill a pot or deep roasting pan with enough water to submerge the filter and bring to a hard boil.
- Stir in 1/4 cup baking soda per gallon of water. It will fizz briefly.
- Drop the filter in, reduce to a simmer, and let sit 10 to 15 minutes.
- Lift out with tongs, scrub with a soft-bristle brush, rinse under hot tap water, air dry on a towel.
Total cost: about $0.40 in baking soda. Total active time: under 5 minutes.
Method 2: Ammonia Vapor for Hardened Grease
When a filter has not been cleaned in a year, the varnish resists baking soda. Household ammonia (around 5 to 10 percent) saponifies hardened fats. Work outside or with windows wide open.
- Place the filter inside a heavy-duty 2-gallon zip bag.
- Pour in 1/2 cup of plain ammonia (not lemon-scented, not with detergents).
- Seal, leaving as much air as possible. The fumes do the work, not direct contact.
- Let sit overnight outside, in a garage, or in a shed.
- Open the bag outdoors, remove the filter with gloves, rinse thoroughly, and wash with dish soap and hot water.
Never mix ammonia with bleach or any chlorine product. The reaction creates chloramine gas, which sends people to the ER every year. Pine-Sol, Tilex, and Comet are all incompatible.
Method 3: Dishwasher Cycle
Most aluminum mesh filters survive the dishwasher fine, but they often emerge oxidized to a dull gray. This is cosmetic and does not affect airflow.
- Stand the filter vertically on the bottom rack, mesh side down.
- Use a degreaser-strength tab like Cascade Platinum Plus or Finish Quantum Ultimate.
- Run the hottest cycle your dishwasher offers, typically a Heavy or Pots cycle at 140 to 150 degrees F.
- Skip the heated dry to limit oxidation and pull the filter while still warm.
Stainless steel mesh filters from Vent-A-Hood, Best, and Zephyr handle the dishwasher with no oxidation issues. Painted or anodized filters from older Broan hoods can lose their finish, so check the back of the filter for a manufacturer label first.
Method 4: Commercial Degreaser
For commercial-style hoods or filters that have not been touched in two-plus years, reach for a true degreaser. Krud Kutter Original ($7 for 32 oz at Home Depot), Zep Heavy-Duty Citrus Degreaser, and Simple Green Pro HD all work in the 12 to 13 pH range. Mr. Clean is too mild. Easy-Off Heavy Duty Oven Cleaner is too caustic and will pit aluminum.
- Spray the filter on both sides until fully wet.
- Let dwell 10 minutes, keeping the surface wet by re-spraying once.
- Scrub with a stiff nylon brush, not metal wool. Aluminum scratches easily.
- Rinse with hot water and dry on a towel.
Charcoal Filters Are Different
If your hood vents recirculate (no duct to the outside), it likely has a secondary charcoal filter behind the mesh. Charcoal cannot be cleaned. It absorbs odor molecules until saturated, then has to be replaced. Broan, GE, and Whirlpool sell replacements for $25 to $60. Plan on a fresh charcoal filter every 6 to 12 months depending on cooking volume. Ductless hoods are inherently less effective than vented ones, so cleaning the mesh and replacing the charcoal on schedule matters more.
How Often to Clean
Use these intervals from manufacturer guidelines and EPA indoor-air guidance:
- Daily heavy frying or stir-frying: every 14 to 21 days
- Average household with 4 to 6 sauteed dinners a week: every 30 days
- Light cooking, mostly oven and microwave: every 60 to 90 days
- Vacation rental or rarely used kitchen: every 6 months minimum
Pair filter cleaning with a 30-second wipe of the underside of the hood. Grease that drips off the filter pools on the hood floor and starts the next layer.
Pro Tips for Long-Term Performance
Run the fan on low at the start of cooking, not after smoke appears. Pre-emptive airflow captures vapor before it migrates to your cabinets. Keep the hood on for three to five minutes after you finish to clear residual humidity. Always cook on the back burners when possible. They sit directly under the filter, where capture efficiency is closer to 90 percent versus 60 percent on the front burners. Combine those habits with quarterly cleaning and your filter mesh will outlast the appliance.
When to Replace Instead of Clean
Aluminum mesh filters wear out eventually. Signs it is time for a new one: dented or bent mesh that no longer sits flush in the hood frame, broken handle clips that will not seat, corroded edges, or a filter that has been cleaned with oven cleaner and now flakes anodized coating. Replacements run $12 to $35 from the manufacturer and ship overnight from sites like AppliancePartsPros, Repair Clinic, and Sears Parts Direct. Match the OEM model number for an exact fit. Universal replacements rarely seal properly and let grease past the filter into the duct, which is a fire hazard. Most manufacturer warranties cover original filters for one to two years, with replacements available for 10-plus years on common Broan, GE, and Whirlpool hoods.
