A range hood that won't pull smoke is grease-clogged filters 60% of the time — a $0 dishwasher fix. The rest split between a stuck back-draft damper, a crushed duct, a recirculating-mode charcoal filter that needs replacement, or (rarely) a failed motor. Below: the seven causes in the order we find them and the four free DIY checks before you call.
Reviewed by Mike Larson, Master Appliance Technician · 18+ yrs in-field · Last reviewed
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Quick answer
Try in this order: (1) pull the metal mesh / baffle filters and run them through the dishwasher with grease cycle — solves ~60% of weak-suction calls for free; (2) reach in and feel the fan blade — caked grease cuts airflow in half; clean it; (3) go to the roof or wall cap and confirm the damper opens when the fan runs; (4) if you're in recirculating mode (no duct out), replace the charcoal filter every 6 months. If suction is gone entirely and the motor still runs = damper / duct. If motor doesn't run = control or motor itself ($285–$485).
Root causes, ranked by what we find
What it is: The metal filters that catch grease are washable but rarely washed. Two years of cooking can cut suction by 70%. Symptom: hood runs, weak suction across all speeds.
Fix: Pull the filters (slide / squeeze the spring tabs). Run through the dishwasher on a hot grease cycle. Hand-scrub stubborn buildup with degreaser. Free.
Typical all-in: DIY · $0
What it is: Even with clean filters, grease that bypassed them coats the squirrel-cage blower. Imbalance + drag = noise and weak flow. Symptom: hood louder than it used to be, weak airflow.
Fix: Power off at the breaker. Remove the filters; reach in and degrease the visible blower blades. Service appointment for a deep clean ($185–$245) on stubborn hoods.
Typical all-in: DIY · $0 / Service $185–$245
What it is: Spring-loaded damper at the wall or roof cap is stuck closed by grease or paint. Motor runs but air can't leave. Symptom: full motor noise, zero face suction, sometimes back-pressure tone.
Fix: Inspect the damper at the duct outlet — exterior wall cap or rooftop. Free it up, lubricate the pivot. $185–$265 if motor + damper accessed from the hood side.
Typical all-in: DIY $0 / Service $185–$265
What it is: Hoods over kitchen islands often recirculate (no duct out) — air passes through a charcoal filter and back into the room. Filter saturates in 4–6 months. Symptom: hood runs normally but kitchen still smoky and smells linger.
Fix: Replace the OEM charcoal filter. Most platforms it slides in behind the metal mesh. $25–$65 part, 5-minute swap.
Typical all-in: $25–$65 part
What it is: Flex duct kinked behind the hood, or the rigid duct disconnected in the attic / wall. Symptom: weak suction with everything clean and damper free; smoke visible above the hood in the cabinet.
Fix: Inspect from the hood up. Re-route or replace the duct run with smooth 6" rigid where possible. $185–$385 depending on access.
Typical all-in: $185–$385 all-in
What it is: Capacitor weak or motor windings degraded. Symptom: runs at low but not high, or hums and doesn't spin, or dead on one speed only.
Fix: Replace OEM blower assembly (most platforms it's a sealed motor + squirrel cage unit).
Typical all-in: $285–$425 all-in
What it is: Membrane control fails on Zephyr, Best, KitchenAid touch-controlled hoods. Lights may still work via separate switch. Symptom: hood unresponsive to fan speed buttons.
Fix: Replace OEM control board / touch panel. Often back-ordered on lower-volume hoods — ask first.
Typical all-in: $285–$485 all-in
Diagnostic order
Slide or squeeze the spring tabs to release. They lift out the front of the hood.
Hot grease cycle, top rack. Hand-scrub stubborn buildup with kitchen degreaser. Dry before re-installing.
Power off at the breaker. With filters out, reach in and degrease whatever blower blade you can see. Paper towel + spray degreaser.
Island hoods without a duct out use a charcoal filter behind the mesh. Replace every 4–6 months — $25–$65 OEM part.
Run the fan, watch the exterior cap. The flap should swing open. Stuck closed = clean and lubricate the pivot.
Motor or membrane control — $285–$485. Same-day windows weekdays before 2pm.
FAQs
Grease-clogged filters 60% of the time — pull them, run through the dishwasher on a hot grease cycle, re-install. Free. Next suspect: caked grease on the squirrel-cage blower blade. Last suspect on a ducted hood: stuck back-draft damper at the wall or roof cap (motor runs, zero face suction).
Stuck back-draft damper — the spring-loaded flap at the exterior wall or roof cap is stuck closed by grease or paint. Motor runs but air can't leave. Inspect at the exterior cap with the fan running and free the flap. $185–$265 service if access from the hood side is needed.
Every 2–4 weeks if you cook daily with oil, every 2 months for light cooking. Dishwasher with grease cycle, top rack. Charcoal filters in recirculating (ductless) island hoods get replaced every 4–6 months — they aren't washable.
Filter clean: DIY $0. Charcoal filter: $25–$65. Damper service: $185–$265. Duct repair: $185–$385. Motor / blower assembly: $285–$425. Control board: $285–$485. Trip $149 waived on approval. Most calls finish first visit.
Touch / membrane controls fail on these brands past year 7 — lights may still work on a separate switch. Replace the OEM control panel ($285–$485). Lower-volume Wolf and Zephyr panels sometimes back-order — we check stock when we book.
Grease buildup in the filters, blower, and duct is the leading cause of kitchen fires from cooking equipment. A weak hood almost always means accumulated grease — clean the filters and inspect the duct annually. If your duct hasn't been inspected in years, ask for a duct cleaning at the same call.
Related coverage
See all range hood repair services.
What will this cost?
Trying to decide repair vs. replace? These pages break down real all-in pricing by brand, model class, and failure mode — so you know the number before we knock.
