Commercial Commercial Charbroiler: Excessive Flare-Ups — Causes & Fixes
Compiled by Resultex Media Group · Editorially reviewed · Last verified August 2026
Check in this order (5-minute diagnostic)
Work top to bottom — the quickest, most-likely checks are first.
- Grate not tilted / grease not draining. Grease pooling on the grates instead of running off usually means the reversible grate is set flat instead of sloped toward the front trough.
- Dirty grates and heavy grease build-up. Carbon and grease on the grate rods (especially the underside) and on radiants trap fat and feed flare-ups.
- Water pan / water tub empty or grease trays full. On water-bath units, a dry water pan lets dripping grease flame instead of being quenched; overfull grease/crumb trays also feed fires.
- Heat too high for a fatty product. Flare-ups spike with fatty cuts on a very hot grill (manufacturer flare-up chart: high heat + high fat = maximum flare-up).
Likely causes, checks & fixes
| Likely cause | How to check | What to do | Who |
|---|---|---|---|
| Grate not tilted / grease not draining | Grease pooling on the grates instead of running off usually means the reversible grate is set flat instead of sloped toward the front trough. | Set the top grate to the tilted/sloped position for all broiling so grease drains to the front grease trough; use the flat position only for pots, never to broil. | DIY-safe |
| Dirty grates and heavy grease build-up | Carbon and grease on the grate rods (especially the underside) and on radiants trap fat and feed flare-ups. | Scrape the grates during and after service with a wire brush/scraper, clean the underside of the rods, and clean radiants/lava rock on schedule when cool. | DIY-safe |
| Water pan / water tub empty or grease trays full | On water-bath units, a dry water pan lets dripping grease flame instead of being quenched; overfull grease/crumb trays also feed fires. | Keep the water pan/water tub filled (never let it run dry) and empty and clean the grease box and crumb/deflector trays daily when cool. | DIY-safe |
| Heat too high for a fatty product | Flare-ups spike with fatty cuts on a very hot grill (manufacturer flare-up chart: high heat + high fat = maximum flare-up). | Lower the burner valve for fatty products and manage load size; run a lower finishing zone for high-fat items. | DIY-safe |
Who can do it: DIY-safe owner-doable · Basic simple part swap · Technician refrigerant/gas/electrical — call a licensed pro.
How to do the safe fixes
Owner-doable procedures only. Anything on the "Technician" list above needs a licensed pro.
Light the standing gas pilots (radiant charbroiler) Basic
- Turn the main gas shut-off valve and all individual burner valves OFF and wait 5 minutes to clear any gas.
- Turn the main gas shut-off valve back ON.
- Pass the lit ignition source through the pilot access/sight hole in the front panel and light each pilot in turn (the flame end must reach the pilot inside the unit).
- Confirm each pilot holds a small, steady flame (a slight yellow tip is normal on a standing pilot); if a pilot won't stay lit, stop and see the 'pilot won't stay lit' section.
- Once all pilots are lit, turn the individual burner valves to MAX to light the burners, then adjust to the desired setting.
- If any burner fails to light, turn all burner valves and the main gas shut-off to OFF and contact an authorized service agency.
· Tools: Long fireplace/BBQ lighter or match holder (reach at least ~7" past the front panel), Flathead screwdriver (only if the manual calls for a pilot flame adjustment), Heat-resistant gloves · Source: Vulcan/Wolf VACB/ACB Installation & Operation Manual (lighting the gas pilot); Star Ultra-Max manual (pilot lighting - wait 5 minutes, light pilots, then burners)
Relight a safety-pilot / runner-tube model (e.g., MagiKitch'n -S) Basic
- Turn all burners OFF. If the pilot just went out, wait 5 minutes before relighting to let residual gas dissipate.
- Remove the top grid and, on radiant models, a radiant to reach the runner tube.
- Turn the shut-off valve to ON, then press and hold the reset (blue) button on the safety pilot valve and wait 15-30 seconds.
- With the reset button still held, light the runner tube; if it doesn't catch, wait a few seconds and try again (first light after connecting gas can take 1-2 minutes).
- Keep holding the reset button an additional 15-30 seconds, then release it — the runner tube should stay lit. If it goes out, repeat; if it fails after three attempts, contact an authorized service agent.
- Replace the radiant and top grid, then push and turn the individual burner valves to light the burners.
· Tools: Long ignition source, Heat-resistant gloves · Source: MagiKitch'n 600 Series Gas Broiler Installation-Operation-Maintenance manual (RMB/SMB -S models with safety pilot)
Clean the grates, radiants, and lava rock (safe daily/periodic cleaning) DIY-safe
- Scrape the top grates with a wire brush during and after service, cleaning the underside of the rods so grease keeps draining forward.
- When the unit is cool, remove the grates and radiants and clean away fat, grease, and food; soak grates in degreaser (overnight if heavily caked), rinse thoroughly, dry, and re-oil to prevent rust.
- Reinstall one radiant per burner (never run the unit without radiants).
- For lava-rock units, monthly remove the rock, soak it overnight so grease separates, clean the lava grates, drain, and replace the ~2" pieces about one layer thick (never exceed the manufacturer's rock limit).
- Empty and wash the water pan/tub, grease box, and crumb/deflector trays; keep deflector-tray holes clear and reinstall trays correctly.
- Do not scrape or poke the burners or their ports, and do not use a water jet on the unit.
· Tools: Wire grill brush and scraper, Heat-resistant gloves, Detergent/degreaser or approved commercial grate cleaner, Bucket (for lava-rock soak) · Source: Vulcan/Wolf VACB/ACB manual (cleaning grates, radiants, trays); Star Ultra-Max manual (grate/water pan/lava rock cleaning); MagiKitch'n 600 (daily cleaning and maintenance)
Keep burner ports and the burner area clear (what's owner-safe vs. technician-only) DIY-safe
- With the unit OFF and cool, remove the top grates and radiants (or lava rock) and brush away carbonized debris that has fallen onto and around the radiants/burner shields.
- Wipe the burner area free of loose crumbs and grease so debris isn't sitting where it can block combustion; keep the crumb/deflector tray clean and the air-inlet area at the bottom/front of the unit unobstructed.
- Do NOT run a brush, wire, or tool into the burner ports, and do not remove burners, orifices, or the air shutters to 'clean' them — port, orifice, and shutter cleaning on gas equipment is a qualified-technician task.
- If burners are burning unevenly, have visibly blocked ports, or produce yellow/lifting flames after this cleaning, call an authorized gas service agency rather than disassembling anything.
· Tools: Wire brush/scraper, Heat-resistant gloves · Source: Star Ultra-Max manual ('brush out carboned particles'); Vulcan/Wolf VACB/ACB manual (radiants/burners; burner and shutter adjustment by trained personnel; annual technician inspection)
- A breaker that trips again after you reset it once — stop, disconnect the unit, and call an electrician or refrigeration technician.
- You smell gas, see refrigerant/oil leaking, or the repair needs the sealed system, gas train, or high-voltage wiring.
Related commercial charbroiler problems
Frequently asked questions
Why is my commercial charbroiler excessive flare-ups?
Some flare-up is normal and even desirable for char flavor, but excessive flare-up burns food, leaves a bitter taste, and is a real grease-fire hazard. It is almost entirely an operator/maintenance issue: cook with the top grate in the tilted (sloped) position so grease drains to the front trough, keep the grates clean (especially the underside of the rods), keep the water pan/water tub filled, empty the grease/crumb trays daily, and lower the heat for fatty products. The manufacturers' formula: higher heat plus higher fat content equals more flare-up. Never leave a charbroiler unattended, and make sure the hood fire-suppression system and a Class K extinguisher are in place.
Is it worth repairing or replacing?
Simple fixes (gaskets, coil cleaning, a single part) are worth repairing. Consider replacing when it needs a compressor or sealed-system repair and is 8–10+ years old, or when repeat service calls near the price of a new unit.
- Vulcan/Wolf Gas Charbroilers VACB25-VACB72 / ACB25-ACB72 Installation & Operation Manual (Form F38328), incl. lighting, cleaning, maintenance, and troubleshooting — source
- Star Ultra-Max Gas Radiant & Lava Rock Charbroiler Owner's Manual (models 80xx/81xx), 2M-Z20327 Rev. D — source
- MagiKitch'n 600 Series Gas Broiler Installation-Operation-Maintenance Manual (RMB/SMB, incl. safety-pilot models), L25-001 R5 — source
- PartsFE - Common Vulcan Charbroiler Issues & How to Fix Them (dealer troubleshooting reference) — source
- FDA Food Code (safe cooking temperatures, Sec. 3-401.11) — source
- NFPA 96 - Standard for Ventilation Control and Fire Protection of Commercial Cooking Operations — source
- NFPA 10 - Standard for Portable Fire Extinguishers (Class K for kitchen grease fires) — source
- OSHA - commercial kitchen fire and burn hazards (restaurants) — source