Foundry Line Appliance — +1 (904) 605-5889 A blower at full speed that still lets smoke cross the room is usually starved of make-up air or fighting a bad duct. Neither is a motor fault. Source: https://jaxviking.com/shop-notes/hood-airflow-and-make-up-air/ --- - Home / - Shop Notes / - Shop Note 004 Shop Note 004 # Loud Hood, Room Full of Smoke Noise is not airflow. Before anyone buys a blower, open a window and run the hood again. That test is free and it settles most of these. ![Wide kitchen frame over an open professional range with the extraction canopy above the cooking surface](/img/rangetop-burner-05.webp) Air pulled out of a tight house has to be replaced from somewhere. Posted August 4, 2026 The complaint arrives in one sentence, almost word for word every time: the hood is loud but the smoke still comes at me. It is a good description and it points straight at the answer, because noise and airflow are not the same thing. A blower makes most of its noise from the motor and from air moving through the housing. It will happily make all of that noise while moving very little air, if something downstream or upstream will not let the air through. Which is why the first question is never “is the motor working” but “where is the air stuck”. ## Free test number one: the filters Baffle filters lose free area as grease loads them, and they do it gradually enough that nobody notices. A set of filters that have gone dull and slightly tacky are restricting the system meaningfully. Most of them come back with a dishwasher cycle and a degreaser. If cleaning the filters changes the capture, that was the whole problem. We would rather tell you that on the phone than charge you to discover it. ## Free test number two: open a window If the filters are clean and capture is still poor, crack a window near the kitchen and run the hood again. If the smoke suddenly starts going up the hood, the blower is fine. The house is the problem. Here is the mechanism. A high-capacity hood removes a real volume of air from the building. That air has to be replaced, and it will be replaced through whatever openings exist. In a tightly built house — most newer construction in the Deerwood, Baymeadows and Bartram Park corridor — there are very few openings, so the blower ends up working against a partial vacuum. Fan curves fall off steeply under pressure. The motor draws its current, makes its noise, and moves a fraction of its rated air. Cracking a window supplies make-up air by hand and proves it in thirty seconds. The permanent fix is a make-up air path, which is a mechanical contractor’s work, not an appliance repair. It is also the thing that will actually solve the problem, so we say it rather than selling a blower. ## When the duct is the problem instead The opposite case shows up in Riverside, Avondale, Old Ortega and San Marco. A 1915 frame house leaks enough air that make-up is never the constraint. There the constraint is the duct run, because there was rarely a short straight path from the cooktop to an exterior wall through plaster and lath and a century of additions. Long runs, multiple elbows and any reduction in diameter all cost static pressure. A duct that has been squeezed down to fit a joist bay is a permanent restriction, and no blower fixes it. We look at the run, count the turns and check the diameter before quoting anything. ## What actually is a motor fault There is a real motor failure and it sounds different. Bearing wear produces a rumble or hum that appears at one speed and vanishes at another, because the resonance only lines up at certain revolutions. That is a motor on borrowed time and it will usually seize during the week you need it most. Losing the middle speeds while the top and bottom still work is a control fault, not a motor fault — a dead motor is dead at every setting. Lights working while the fan does nothing proves power is reaching the hood, which is worth establishing before anyone opens a wall. ## The damper nobody checks Backdraft dampers live out of sight in the duct and they stick. One that will not open throttles the entire system while everything visible looks perfect. One that will not close lets humid outside air, and sometimes insects, back down into the kitchen, which in a Jacksonville August is a problem of its own. We check it. It is a small thing that explains a lot of hoods that have never worked properly since the day they were installed. Flat diagnostic, credited toward the repair. Written estimate first. Independent shop, not affiliated with or authorized by the manufacturer. Related ## The work this belongs to Ventilation & Hoods ### Viking Hood and Ventilation Repair Blowers that roar without clearing smoke, dead speed settings, and dampers that never open. Wall, island and insert ventilation. Sector 32256 ### Viking Repair in Deerwood and Baymeadows Late-model southside houses built tight, where a big blower has nowhere to draw make-up air from and one kitchen carries five separate systems. Sector 32205 ### Viking Repair in Riverside and Avondale A professional range in a bungalow kitchen built before the appliance existed. Long duct runs, shared circuits, and floors that have moved for a century. Sector 32223 ### Viking Appliance Repair in Mandarin Large kitchens, island hoods on long duct runs, and a lot of refrigeration installed in garages and lanais where the air conditioning does not reach. Book the visit ## Tell us the model. We bring the part. Viking only. Duval County, citywide. Flat $129 diagnostic. It is credited toward the repair if you approve the work. Call +1 (904) 605-5889 Send the details - Diagnostic: $129 flat - Labor: 90 days on labor - Parts: 365 days on parts - Weekdays: Mon–Fri, 8am–6pm - Saturday: Sat, 9am–4pm --- Foundry Line Appliance. To book a visit, telephone +1 (904) 605-5889. Foundry Line Appliance is an independent appliance repair company. We are not affiliated with, authorized by, or endorsed by Viking or its parent company. All brand names and model numbers are the property of their respective owners and are used only to identify the appliances we service.