Restaurant hood grease filters can usually be cleaned when they are removable and structurally sound. The safe process is to shut down the equipment, remove the filters carefully, inspect them, degrease and rinse them, dry them completely, and reinstall them correctly.
Filter cleaning is only one part of commercial kitchen exhaust maintenance. Stop and arrange qualified service if you find damaged filters, grease inside the hood or duct, unsafe access, electrical or fan issues, or buildup that creates a fire hazard.
Quick summary
- Work only when cooking equipment is cool and the hood fan is safely shut down.
- Inspect each filter before washing. Clean sound filters, exchange them when a clean spare is available, and replace filters that are damaged or repeatedly saturated.
- Remove loose grease, apply a suitable degreaser according to its label, rinse thoroughly, and dry the filters fully.
- Reinstall every filter in its correct track and direction, then check grease cups, hood edges, visible residue, and airflow symptoms.
- Record the date, filters checked, defects found, action taken, and photographs. Ontario operators must check hoods, ducts, and filters for combustible deposits at intervals of no more than seven days.
Before You Start: Know When Filter Cleaning Is Safe
Removable baffle or grease filters capture grease before it travels farther into the exhaust system. Routine washing can be appropriate for kitchen staff when the task is limited to accessible filters and the work area can be controlled safely.
Ontario’s Fire Code requires hoods, ducts, and filters subject to combustible deposits to be checked at intervals of no more than seven days. They must be cleaned when accumulation creates a fire hazard. Cooking operations that produce smoke or grease-laden vapours also require exhaust and fire-protection systems maintained in accordance with NFPA 96. See the Ontario requirements for checking combustible deposits and maintaining commercial cooking exhaust systems.
Before removing a filter, confirm that:
- The cooking equipment and nearby surfaces are cool enough to work around safely.
- The exhaust fan is off and cannot start unexpectedly.
- The floor is dry and stable, with no unsafe ladder or rooftop access required.
- You have suitable gloves, eye protection, cleaning materials, a controlled wash area, and a way to contain grease and wastewater.
- The work will not expose staff to energized electrical parts, moving fan components, or strong chemicals.
Do not repair a fan, handle wiring, enter ductwork, climb onto a roof, or clean inaccessible exhaust components as part of routine filter washing. Stop if a filter is stuck, dangerously heavy, sharp, corroded, or likely to fall.
Step 1: Inspect the Filters Before Washing
Identify the filter type and note how each one is seated. Many commercial hoods use removable baffle filters with a frame and internal channels. Follow manufacturer markings for orientation, and do not assume filters from different sections are interchangeable.
Look for:
- Heavy grease saturation, dripping, or film that returns immediately after cleaning.
- Warped baffles, bent frames, crushed corners, broken handles, loose parts, or corrosion.
- Blocked channels that cannot be cleared by normal washing.
- Gaps in the filter track or evidence of incorrect installation.
- Damage that prevents the filter from sitting securely or maintaining its intended airflow path.
If the filter remains sound and the grease can be removed, continue with cleaning. If its structure is compromised or saturation returns unusually quickly, cleaning may not be enough. Guidance on cleaning, exchanging, or replacing exhaust filters can help with that decision.
Step 2: Shut Down the Hood and Remove Filters Carefully
Choose a service window that gives staff enough room to work without rushing. Keep food, utensils, packaging, and other food-contact items away from the cleaning area. Wear gloves and eye protection when handling greasy metal or degreasing products.
Support each filter with both hands as you remove it. Grease can make a filter heavier than expected, and a sudden drop can damage the filter, hood track, floor, or nearby equipment. Keep the filter level where possible so grease does not spill onto the cooking line.
Place removed filters in a designated wash area or container. Do not carry dripping filters through food preparation areas if you can avoid it. Remove grease cups or trays only when they are designed for routine staff removal and can be handled without spilling their contents.
Step 3: Remove Grease, Degrease, Rinse, and Dry
Start by removing loose grease with a scraper or disposable material suitable for the filter surface. Collect the waste instead of washing large amounts directly into a drain. Excess grease can create plumbing problems and makes later cleaning less effective.
Apply a commercial degreaser suitable for the filter material and use it exactly as directed on the label. Do not mix chemicals, improvise concentrations, or use a product that could damage aluminum, stainless steel, seals, coatings, or surrounding surfaces. Follow the product’s required protective measures.
Work the cleaner through the filter channels and frame, paying attention to corners and grease collection points. Use a brush that will not gouge the metal. If heavy deposits do not release with normal cleaning, do not escalate to unsafe chemicals, excessive force, or uncontrolled heat. Set the filter aside for professional cleaning or replacement.
Rinse thoroughly until cleaning residue and loosened grease have been removed. Inspect the channels while the filter is wet. A filter that still has blocked passages, persistent tacky buildup, or damage should not be returned to service simply because its outside surface looks cleaner.
Dry the filter completely before reinstalling it. Water left in the channels can carry residue into the hood and contribute to renewed buildup. Use a clean, suitable drying area and never place wet filters back over hot cooking equipment.
Step 4: Decide Whether to Clean, Exchange, or Replace
The correct outcome depends on the filter’s condition, not just how dirty it looked.
| Action | Use it when | Next step |
|---|---|---|
| Clean | The filter is straight, intact, free of significant corrosion, and returns to a clean condition after degreasing. | Dry it fully, reinstall it correctly, and monitor its performance. |
| Exchange | The installed filter is sound but needs cleaning, while a properly sized clean spare is available. | Install the clean spare and place the removed filter into the normal cleaning rotation. |
| Replace | Baffles are warped, the frame is bent, parts are broken, corrosion is significant, or saturation returns immediately after cleaning. | Confirm compatibility with the hood system before installation. |
Do not treat a filter as acceptable merely because it fits the opening. A damaged or poorly seated filter can leave gaps, rattle, restrict intended airflow, or allow more grease into the exhaust system. Product specifications and the hood manufacturer’s requirements should guide filter selection.
Step 5: Reinstall Filters and Check the Surrounding Hood
Before reinstalling, check that each filter is dry and free from loose residue. Slide it into the correct track without forcing it. If the filter has an airflow arrow or orientation marking, follow it. Confirm that the frame sits securely and adjacent filters do not leave unintended gaps.
Clean accessible grease cups, trays, and nearby hood edges as part of the closeout. Wipe surrounding surfaces without pushing grease into the filters. Look for visible drips, streaks, or residue inside the hood and around the filter tracks.
After returning the equipment to normal operation, pay attention to smoke lingering under the hood, unusual noise, fan belt squeal, vibration, or greasy odors outside the kitchen. These signs can indicate a ventilation or exhaust-system issue that filter washing alone will not solve.
Clean filters are one element of restaurant fire safety standards. They do not replace inspection and maintenance of the hood, plenum, duct, exhaust fan, grease containment, or fire-protection system.
When Filter Cleaning Is Not Enough
Arrange broader commercial kitchen exhaust service when grease extends beyond the removable filters. This includes buildup on the hood interior, plenum, ductwork, fan blades, fan housing, rooftop shroud, or grease-containment components.
Escalate the job if you notice:
- Persistent smoke or weak capture after clean, correctly seated filters are installed.
- Grease streaking on the rooftop fan, hood exterior, duct access areas, or nearby roof surface.
- Fan belt squeal, slipping, unusual vibration, or other mechanical symptoms.
- Grease dripping from inaccessible areas or deposits that require access panels.
- A need to work at height, near electrical equipment, inside ductwork, or on a fan that has not been safely isolated.
- Combustible buildup that may already constitute a fire hazard.
Filter washing should be part of a coordinated maintenance plan, not a substitute for full exhaust cleaning. Wider service may include hood and plenum degreasing, duct cleaning, exhaust fan cleaning, filter exchange, fan belt checks, and grease containment maintenance.
Ontario Checks, Maintenance Records, and Scheduling
Assign responsibility for checking the hood, ducts, and filters at least every seven days when combustible deposits may be present, as required by Ontario’s Fire Code. A check is not the same as automatically washing every filter on the same schedule. Cleaning frequency should reflect cooking volume, grease load, fuel type, visible buildup, airflow symptoms, and inspection findings.
Use a simple maintenance record for every check or cleaning. Include:
- Date and time of the inspection or cleaning.
- Hood, filter set, grease cups, and other components checked.
- Condition found, including damage, heavy saturation, residue, or airflow concerns.
- Action taken, such as washed, exchanged, replaced, escalated, or scheduled for service.
- Name or initials of the person completing the work.
- Photographs of defects, completed cleaning, or components requiring follow-up.
Coordinate filter washing with a broader hood cleaning frequency and maintenance schedule. High-output cooking lines may need more frequent attention than low-volume or seasonal operations, so use documented inspections to adjust the routine.
Restaurant Hood Filter Cleaning Checklist
- Equipment is cool, the hood fan is safely shut down, and the work area is controlled.
- Protective equipment is being used, and the cleaning product is appropriate for the filter material.
- Each filter has been inspected for warping, corrosion, bent frames, and broken parts.
- Loose grease has been collected rather than washed carelessly into the drain.
- Degreaser has been used according to its label, without mixing products.
- Filters have been rinsed thoroughly and dried completely.
- Damaged or repeatedly saturated filters have been exchanged, replaced, or escalated.
- Filters are seated in the correct tracks and orientation, with no unintended gaps.
- Grease cups, trays, accessible hood edges, and visible residue have been checked.
- Smoke, odor, vibration, belt noise, or weak capture has been reported for follow-up.
- The date, condition, action taken, and photographs have been recorded.
Frequently Asked Questions
How often should restaurant hood grease filters be cleaned?
There is no single interval for every restaurant. Check the hood, ducts, and filters for combustible deposits at intervals of no more than seven days in accordance with Ontario’s Fire Code, then clean when buildup creates a fire hazard. The washing schedule should reflect cooking volume, grease load, fuel type, and inspection findings.
How do I know whether a hood filter should be replaced instead of cleaned?
Replace or arrange an exchange when baffles are warped, the frame is bent, parts are broken, corrosion is significant, or grease saturation returns immediately after cleaning. A sound filter that becomes clean and remains secure can usually continue in the cleaning rotation.
Can restaurant hood filters go in a commercial dishwasher?
Only if the filter and equipment manufacturer permit that method. Confirm compatibility first because the wrong process can damage the filter, spread grease, or contaminate equipment. Follow approved instructions for the specific filter material and system.
Does cleaning grease filters replace professional hood and duct cleaning?
No. Filter washing addresses removable filters only. Grease can also accumulate in the hood, plenum, ducts, exhaust fan, and containment components, which may require qualified commercial kitchen exhaust service and safe access equipment.
What should be recorded after cleaning commercial kitchen hood filters?
Record the date, components checked, filter condition, cleaning or exchange performed, defects found, corrective action, person completing the work, and relevant photographs. Documentation supports a repeatable process but does not replace physical inspection and cleaning.
Make Filter Cleaning Part of a Wider Exhaust Maintenance Plan
The safest approach is straightforward: clean removable filters when they are structurally sound, exchange them when a clean spare improves the maintenance rotation, and replace them when damage or persistent saturation means washing is no longer enough. Always stop when the task extends to unsafe access, electrical or fan work, chemicals beyond staff capability, or grease in the wider exhaust system.
Regular filter care should sit alongside documented checks and planned hood, duct, fan, and grease-containment maintenance. For filter cleaning and exchange, hood and duct cleaning, exhaust fan maintenance, or related commercial kitchen services across Ontario, contact Robinhood Cleaners.