Hearth & Range Service Co. — (904) 478-8963 — Independent Wolf cooking appliance repair, Jacksonville, FL # Ventilation hood repair Source: https://firstcoastwolf.com/what-we-fix/ventilation-hood/ Updated: 2026-08-10 A professional hood is a blower, a duct, a set of baffles and a damper, and every one of those can be the reason a kitchen still smells of last night's fish. Coastal air and grease do most of the damage here. ## Noise is not extraction The most common thing we hear about a hood is that it is loud and the kitchen still smells. Those two facts belong together more often than not. A blower that is moving very little air is frequently louder than one moving a lot, because what you are hearing is turbulence and restriction rather than airflow. The paper test settles it in five seconds. Run the hood on high and hold a sheet of paper up against the baffles. If it does not pin itself there, the system is not moving air, and the fault is somewhere between the baffle and the outdoors — not in the motor's willingness to spin. ## Where the restriction usually is Baffles come first, and they are the owner's job rather than ours. Baffle filters are designed to be pulled out and run through a dishwasher, and when they are neglected the grease bridges the gaps and the open area collapses. A hood with clogged baffles works hard and achieves nothing. The duct run comes second, and it is where installation sins show up. Every elbow costs airflow. A long horizontal run costs airflow. Flexible duct where rigid should have been used costs a great deal of airflow. We cannot rebuild a duct run on a service call, but we can tell you honestly when the hood is healthy and the ductwork is the problem, which saves you paying for a blower you did not need. The damper comes third. A backdraft damper is a set of light flaps that should swing open under airflow and fall closed when the hood stops. Grease gums them shut. Salt corrodes the pivots. A damper that only half opens strangles the whole system, and one that will not close lets outside air, humidity and insects come back down the duct. ## The 400 CFM line, and why doors slam If your hood is a serious one and your house is reasonably tight, there is a question worth asking: where is the air coming from? A hood only exhausts what it can replace. Pull several hundred cubic feet a minute out of a sealed house and the house goes negative — interior doors suck shut, exterior doors get hard to open, and in the worst case a combustion appliance somewhere else in the building can be affected. The residential code recognises this and requires makeup air for kitchen exhaust systems rated over 400 CFM. In practice, in this area, we see it most in the newer construction: Nocatee, Shearwater, SilverLeaf and the newer Jacksonville builds are built tighter than a 1950s Mandarin ranch house, and a big hood in a tight house without makeup air behaves badly. The older Riverside and Avondale kitchens have the opposite problem — they leak enough that makeup air was never an issue, but their duct runs were improvised decades ago. ## Salt air eats the outdoor end first Everything about a hood that lives outdoors is on borrowed time in the coastal ZIPs. Roof and wall caps corrode, damper pivots seize, and external blower housings in Ponte Vedra Beach, at the Beaches and in the older streets of St. Augustine age visibly faster than the same hardware ten miles inland. If a hood in a coastal kitchen has become loud, the odds are good that the noisy part is the one bolted to the outside of the house. ## What we do We check airflow, baffle condition, damper operation, blower balance and the control side, and we tell you which of those is your actual problem. We are an independent shop and we are not part of any manufacturer network. The visit is a $129 flat diagnostic, credited toward the repair, with a written estimate before anything is ordered. Genuine OEM parts, 90 days labor, 365 days parts. ## Symptoms and what usually causes them - **The hood is loud but the kitchen still fills with smoke** — Noise without extraction almost always means the air is not getting out: grease-loaded baffles, a crushed or over-elbowed duct run, or a backdraft damper that is no longer opening fully. Hold a sheet of paper to the baffles on high. If it does not stick, nothing is moving. - **The blower has developed a rumble, whine or vibration** — Bearing wear, or grease build-up on one side of the blower wheel putting it out of balance. An unbalanced wheel gets progressively louder and eventually takes the motor with it. - **The hood works but the doors slam when it is on high** — The kitchen is short of makeup air. A high-output hood can pull the whole house negative, and the residential code requires makeup air for exhaust systems over 400 CFM for exactly that reason. - **Outside air, insects or cooking smells come back down the duct** — A backdraft damper stuck open, corroded, or fouled with grease. On the coast the roof or wall cap is usually the first thing salt air takes. - **The hood lights flicker, fail early or will not switch** — Heat and vibration are hard on lamps and their holders, and the switching side of a hood control lives directly in a stream of warm greasy air. - **The controls respond intermittently or a speed has stopped working** — Usually the control board or the speed switching. Grease vapour migrates into the control housing over years and it does not do connections any favours. - **An external or in-line blower has become much louder** — These are mounted in an attic, on a roof or on an outside wall, and they are exposed. Bearing wear plus corrosion in a coastal ZIP is the usual combination. ## Related - /what-we-fix/rangetop.md - /what-we-fix/gas-range.md - /what-we-fix/dual-fuel-range.md - /answers/how-much-hood-airflow-a-kitchen-needs.md - /answers/fitting-a-range-in-an-old-kitchen.md - /answers/storm-season-and-control-boards.md --- **Hearth & Range Service Co. — (904) 478-8963** Telephone is how work is booked; there is no form on this site. - Monday – Friday: 8am – 6pm - Saturday: 9am – 4pm - Sunday: Closed - Coverage: 40 miles by road from Fruit Cove, St. Johns County, Florida Hearth & Range Service Co. is an independent appliance repair company. We are not affiliated with, authorized by, or endorsed by Wolf 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.