Urgent
Kitchen Filling With Smoke During Service
Smoke backing up into the kitchen during cooking usually means your exhaust hood is no longer pulling air effectively — often due to grease buildup blocking airflow.
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
Reduce cooking output immediately to lower smoke volume, and check that hood filters are seated correctly and the fan is running. Contact a certified hood cleaning and exhaust service provider today through Boh to inspect the system, clear any blockages, and restore proper airflow before your next service period.
What's causing it
The most common cause is grease accumulation inside the hood plenum, filters, and ductwork that restricts airflow over time. Baffle filters clogged with grease force the exhaust fan to work harder while moving less air, allowing smoke to spill back into the kitchen. A failed or undersized exhaust fan motor can produce the same result, as can a makeup air system that is not supplying enough replacement air to sustain proper negative pressure. In some cases, a damper stuck in a partially closed position or a blockage in the duct run will cut exhaust capacity even when the fan is running normally.
What happens if you wait
Smoke filling the kitchen during service is a fire risk, a health hazard for staff, and grounds for an immediate shutdown by the health department or fire marshal. Grease-coated ductwork that is not ventilating properly is one of the leading causes of commercial kitchen fires. Every minute the hood is underperforming, grease continues to accumulate in conditions that accelerate ignition risk.
NFPA 96 requires commercial kitchen exhaust systems to be inspected and cleaned at intervals based on cooking volume, and LA County Fire Department inspectors can cite or close an operation with a non-functional or grease-obstructed hood system.
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.
Restaurant HVAC Maintenance
If the hood is clear but smoke persists, an HVAC make-up air imbalance may be the cause
Not sure where to start?
Tell us what's happening and we'll route you to the right provider.