Routine
Strange Smell Coming From the Hood
Burning, rancid, or chemical smells from the exhaust hood usually mean accumulated grease is overheating, or that mold and bacteria have built up inside the duct system.
How fast can we respond?
Standard request
Within 40h
Submit a request today, we coordinate a vetted provider and confirm your slot.
Request serviceBoh coverage
Zero effort
On coverage, this service is scheduled automatically — before it becomes a problem.
See coverage plansWhat to do
Schedule a hood and duct cleaning with a certified exhaust system service provider, and pull and inspect your baffle filters before the appointment to confirm they are not already past the point of rinsing. Check your grease cups and drip trays and empty them if they are full. Keep a record of the service visit date and any findings for your inspection file.
What's causing it
The most common source is grease that has accumulated on baffle filters, the plenum, and duct walls overheating during service and releasing a burning or acrid smell. If the odor is rancid or sour, mold and bacteria have likely colonized moisture-trapped areas inside the duct, especially in kitchens where the hood is cleaned infrequently or the makeup air system is underperforming. A chemical smell can indicate cleaning residue that was not properly rinsed from filters or interior surfaces. Blocked grease cups that are overflowing also concentrate odors at the hood line. Any of these conditions typically worsen over time as buildup compounds.
What happens if you wait
Left unaddressed, grease accumulation increases fire risk incrementally and will eventually bring the system to a level that fails a health or fire inspection. Persistent odors can migrate into the dining room, affecting the guest experience and flagging a deeper sanitation problem. Mold growth inside ductwork can become a health code violation and, depending on severity, may require more invasive and costly remediation than a standard cleaning would have.
LA County Environmental Health and the LAFD both require commercial exhaust systems to be cleaned at documented intervals, and accumulated grease or mold inside a duct system can result in a cited violation requiring proof of corrective action.
How Boh handles it
Boh dispatches a vetted, licensed provider to your location. Every visit is documented — before and after photos, service report, compliance certificate if applicable. You never chase a vendor.
Not sure where to start?
Tell us what's happening and we'll route you to the right provider.