Most range hood complaints start with "it doesn't seem to be pulling smoke like it used to." The owner has been wiping the grease screen, maybe replaced a charcoal filter, and the hood still isn't doing its job. About 40 percent of the time the fix is simple cleaning beyond the grease screen; 30 percent is a maintenance issue you can address yourself; the remaining 30 percent involves something the homeowner can't reach without removing the hood from the wall. This guide covers what you can fix yourself and when to call us.
$89 residential diagnostic, applied toward repair. BHGS #A49573.
Step 1: Clean the grease screens (you knew this)
Grease screens (the metal mesh panels at the bottom of the hood) trap cooking grease before it enters the duct. They should be removed and cleaned every 2-3 weeks for daily-cooking households; monthly for moderate use. Dishwasher works for stainless screens; degreaser plus hot water for aluminum.
If you've been cleaning grease screens regularly and the hood still pulls poorly, the issue is past the screens.
Step 2: Clean the impeller blades (most owners skip this)
The blower impeller (the curved fan blades behind the grease screens) accumulates grease over time even with clean screens. Some grease aerosolizes through screen mesh; over months and years it accumulates on the impeller blades and inside the blower housing. A grease-coated impeller has degraded aerodynamics and can lose 20-40 percent of its rated CFM.
Procedure on most residential range hoods:
- Power off the hood at the wall switch (not just the hood control).
- Remove grease screens.
- Look up into the blower housing. You'll see the impeller blades.
- Use a degreaser (Krud Kutter, Goof Off Heavy Duty, or just hot water + Dawn) and a stiff brush to clean visible grease accumulation.
- Wipe down the inside of the blower housing.
- Replace screens, restore power.
This is something most homeowners can do in 30 minutes once they realize the impeller exists. If your hood still pulls poorly after impeller cleaning, the issue is in the duct or the make-up air balance.
Step 3: Inspect the duct opening at the wall or ceiling
If your hood vents to the outside (most LA homes do for kitchen hoods over gas cooking), the duct exits at a wall cap or roof vent. Inspect from outside:
- Wall cap: usually a plastic or metal hood with a damper flap. Check that the damper opens freely. If the damper is stuck closed (paint stuck, debris stuck), the hood is fighting against a closed duct. About 15 percent of "weak hood" complaints in LA homes resolve at the wall cap damper.
- Roof vent: birds, lint, leaves can block the screen at the top. Inspect during dry weather; clear with a brush.
- Backdraft on windy days: wall caps facing prevailing winds can backdraft, blowing kitchen air back into the hood. Some installations need a wind-resistant cap upgrade.
Step 4: Check for make-up air imbalance (the LA new-construction issue)
Most LA homes built since 2010 have tight building envelopes per California Title 24 energy code. A 600+ CFM range hood (most premium installs are 600-1,200 CFM) pulling air out of a tight house creates negative pressure inside. Without a make-up air supply, the hood has nothing to pull through itself; it's fighting against the house. Symptom: the hood runs but barely moves smoke; opening a window dramatically improves performance.
California building code requires make-up air for hoods rated above 400 CFM in residential construction. Older homes (pre-2010) generally have enough envelope leakage that this isn't an issue. New construction Calabasas, Hidden Hills, Bel Air rebuilds, and post-2015 condo conversions in WeHo and downtown sometimes have hoods that perform poorly because the make-up air system was undersized or never installed.
If you see significant performance improvement when you open a kitchen window, the issue is make-up air balance. The fix is mechanical/HVAC scope (make-up air unit installation, sometimes a damper-controlled motorized vent), not range hood repair. We diagnose to confirm and refer to HVAC partners.
When professional cleaning is the right call
If you've cleaned screens and impeller and the hood still pulls poorly, the duct itself probably has accumulated grease. Range hood ducts in heavy-cooking households (daily wok cooking, frequent fried-food preparation) can accumulate grease in the duct walls over 3-5 years even with clean screens. The duct buildup degrades CFM and creates a fire risk.
Professional range hood cleaning service includes:
- Removal of the hood from the wall (or partial removal for access)
- Disassembly of the blower assembly
- Degreasing the impeller, blower housing, and accessible duct sections
- Inspection of the duct for grease buildup; brush + vacuum cleaning of accessible runs
- Reassembly and CFM verification
Residential professional cleaning runs $300-540 typical. Commercial restaurant hood cleaning is a separate scope (NFPA 96 compliance) handled by hood-cleaning specialists; we don't do commercial hood cleaning, but we coordinate referrals when commercial customers ask.
When the issue is the blower itself, not the duct
Common range hood mechanical failures we service:
| Failure mode | Year | Repair cost (all-in) |
|---|---|---|
| Blower motor bearings noisy | year 5-9 | $280 to $480 |
| Blower motor failure | year 8-12 | $440 to $720 |
| Speed control switch / module | year 6-10 | $220 to $380 |
| Light socket / bulb harness | year 5-8 | $140 to $260 |
| Damper actuator (motorized) | year 7-10 | $280 to $440 |
| Touch-control panel | year 8-11 | $340 to $540 |
Premium hood brands we service in LA
Common in LA homes: Wolf (matched to Wolf ranges in BH, Bel Air, Calabasas premium installs), Best (Broan family, mid-premium), Zephyr (premium contemporary, common in WeHo modern condos), Vent-A-Hood (premium, common in older estate kitchens with custom hood enclosures), Broan/NuTone (mid-tier, mass-market dominant).
Wolf and Vent-A-Hood are repair-justified through year 12-15. Zephyr through year 10-13. Mid-tier Broan and NuTone through year 8-11; cheaper to replace at year 12+ if multiple failures.
When to call us
If you've cleaned screens, impeller, wall cap, and your hood still doesn't pull smoke, call us. If the hood is making noise (squealing, grinding, bearing whine), call us; that's a motor or fan-cage issue that won't get better on its own. If the lights stopped working but the fan still runs, that's a $140-260 fix usually. If the touch controls are unresponsive, $340-540 typical.
$89 residential diagnostic, applied toward repair. Same-day across LA, OC, Ventura. BHGS #A49573.