Range Hood Vent Cleaning Before Holiday Cooking Season

Range hoods are the unmaintained appliance in most kitchens. They run during cooking, get ignored otherwise, and slowly accumulate grease in the filter, blower wheel, and exhaust duct. November and December are the highest-risk months for kitchen grease fires. Cleaning the hood system in October takes an afternoon and dramatically reduces fire risk during holiday cooking.

The four cleanable zones

1. Filter (baffle or mesh): the metal panels under the hood. Most accessible. Removable
2. Blower wheel: behind the filter, the squirrel-cage fan that pushes air. Reachable but fiddly
3. Duct interior: the rigid or flexible duct from the hood to outside. Mostly inaccessible without professional equipment
4. Exterior cap / damper: where the duct exits the house. Outside

Filter cleaning

Easiest. Should be done every 1-2 months during heavy cooking seasons.

• Remove filters (slide and tilt out)
• Soak in hot water with degreaser dish soap for 20 minutes
• Scrub with a stiff brush, focus on the baffle channels
• Dishwasher cycle on high heat works for stainless filters (not aluminum — alkaline detergent etches it)
• Dry fully before reinstalling

Blower wheel cleaning

This is where the most grease accumulates and where most owners have never looked. Procedure:

1. Kill the hood at the breaker. The blower has a high-current motor
2. Remove the filters
3. Look up — you should see the blower wheel (squirrel cage with curved fins)
4. If you can reach it from below: spray with kitchen degreaser, wait 10 min, wipe with rags. Repeat 2-3 times
5. If you cannot reach it: remove the blower housing — typically 4-6 screws and an electrical connector. Take the blower assembly to a sink, soak in degreaser

Duct interior — why you cannot DIY this

The duct from hood to roof or wall can be 8-30 feet of metal and flex. Grease coats the interior. You need:

• A long rotating brush (50-foot range)
• HEPA vacuum to catch dislodged debris
• Access to both ends of the duct

This is why commercial kitchen hood cleaning is a separate trade — they do it quarterly because of fire code. For residential, every 3-5 years is reasonable, more often if you cook with high-grease methods (frying, stir-fry, searing) frequently.

Exterior cap check

Go outside. Find where the duct exits the house — typically a louvered cap on the roof or exterior wall. Look at it.

• Bird nest in the cap? Common. Disconnects airflow completely
• Damper stuck open? Lets pests and humidity in
• Damper stuck closed? Hood is fighting itself, blower motor is overworked
• Grease dripping down the exterior wall below the cap? Duct is bad and the dripping grease is creating an outside fire hazard

Fan motor warning signs

• Rattling or grinding on high speed — bearing failing
• Speeds 1 and 2 work but 3 does not (or vice versa) — control board or capacitor
• Hood smells like burning during operation — motor windings overheating, replace soon
• Light works but blower does not — blower switch or motor capacitor

Cost

• DIY filter + blower clean: $0 plus 90 minutes
• Berne full hood service (clean blower, check fan motor, test damper, replace bulbs): $185
• Professional duct cleaning (separate service): $300-500

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