--- title: "Chimney fire or smoke in the room: closing the door on a pizza oven flue" description: "Telling overfiring from a burning flue, starving the fire of air without water, smoke spilling under a patio roof or into a dining room, and the inspection that…" url: "https://pizzaovenrepair.center/guides/a-chimney-fire-or-smoke-in-the-room/" date_modified: "2026-09-26" --- Gas, fire, smoke and food # Chimney fire or smoke in the room: closing the door on a pizza oven flue A pizza oven chimney fire is creosote burning inside the flue. Close the oven door to starve it of air, shut the gas on a hybrid or gas unit, keep water out of the dome, move everyone back and call 911 if flame shows at the cap or reaches anything nearby. Smoke in the room means windows open and the fire left to die down. By [PizzaOvenRepair.center technical team](https://pizzaovenrepair.center/authors/technical-team/) Published September 26, 2026 ## At a glance. A roaring flue, sparks spitting from the cap and a pipe too hot to stand near are not a hot bake going well. A pizza oven chimney fire is tar and soot burning inside the flue, and smoke pouring back into a room or under a patio cover is its quieter cousin; both are handled by starving the fire of air, clearing people out and letting professionals judge the damage. Read the whole guide ### The fuel Creosote condensed in the flue Chicago Brick Oven and Marra Forni both say it makes an extremely hot fire once lit. ### First move Door closed, gas off Coyote says to close the door and let the fire die down; NFPA says the same for any oven fire. ### Never Water in the oven or up the flue Coyote forbids water on the bricks or to put out the flame. ### Afterward A professional flue inspection USFA asks for chimneys to be cleaned and inspected by a professional every year. In this guide 1. Flame at the chimney cap or smoke indoors: which one you have 2. Starving a pizza oven chimney fire of air 3. Smoke rolling into the room or the covered patio 4. Where the fuel for a flue fire comes from 5. After the fire, before the next bake 6. Step by step 7. Questions ## Flame at the chimney cap or smoke indoors: which one you have Flame curling out of the oven mouth during a big fire is overfiring, not a chimney fire. Coyote's Duomo manual says flames should never come out of the mouth or up from the chimney, and that too much wood causes it; Alfa warns that a load of wood big enough to push flames out of the chimney cap can cause property damage, injury or death. Both are warnings about the next step: once the flue lining is coated, a run of flame up the pipe can light the coating itself. Smoke in the room is the other failure. It means the flue is not drawing, because it is blocked, too short, cold, or fighting a kitchen exhaust or a gust of wind. It rarely comes with the roar of a flue fire, but it brings carbon monoxide and fine particles into the space where people are standing, so it is treated as urgent too. ### Signs the flue itself is burning - A loud rushing or roaring sound from the pipe, louder than the fire in the dome - Sparks, burning flakes or flame leaving the chimney cap - Thick dark smoke from the cap that keeps coming after the door is closed - Paint blistering or a glow on a metal chimney pipe or its collar - A hot, sharp smell unlike ordinary wood smoke Source: [Coyote — Duomo Wood Fired Pizza Oven Owner's Manual](https://coyoteoutdoor.cdn.prismic.io/coyoteoutdoor/aBI1GfIqRLdaBwbi_Coyote_Wood-Fired_Pizza_Oven_Owners_Manual_2.pdf) — No flames from the mouth or chimney; if it happens, close the door and wait for the fire to die down; never use water on the bricks or to put out the flame; soft and painted wood coat the flue with creosote; [Alfa Forni — User manual, domestic ovens (North America)](https://www.alfaforni.com/download/user-manual/home/user_manual_domestic_ovens-NA.pdf) — Never use so much wood that flames exit the chimney cap; slow burning forms creosote in the flue; inspect for creosote at least twice a year and sweep the flue once a year ## Starving a pizza oven chimney fire of air A wood fire needs air coming in at the mouth to feed anything burning up the flue. Coyote tells owners who see flames from the mouth or chimney to close the oven door and wait for the fire to die down, and NFPA's advice for any oven fire is to turn off the heat and keep the door closed. On a hybrid or gas-fired dome, close the gas at the burner knob and the supply valve if you can reach them without standing under the cap or beside a glowing pipe. Chicago Brick Oven asks every owner to have a clearly understood plan for handling a chimney fire and to ask the local fire authority how to go about it. The plan is short: who closes the door, who closes the gas, who moves guests back, who calls. Settle it before the first party, not while the pipe is roaring. ### Why water stays out of the dome and the pipe Coyote says never to pour water on the bricks or use water to put out the flame, because it will damage the oven. Hot refractory takes a sudden chill badly, and a crack earned that way outlasts the fire by years. Close the door, keep water and garden hoses for anything the sparks set alight outside the oven, and let the fire run out of air. ### When it becomes a 911 call Call 911 when flame shows at the cap, when sparks land on a roof, a pergola, a fence or dry planting, or when a chimney that passes through a roof or wall is running hot. NFPA's rule for fires that are out of control indoors is to get out, close the door behind you and call 9-1-1 once outside. Nobody climbs a ladder to the cap or pulls the pipe apart to look. Source: [Coyote — Duomo Wood Fired Pizza Oven Owner's Manual](https://coyoteoutdoor.cdn.prismic.io/coyoteoutdoor/aBI1GfIqRLdaBwbi_Coyote_Wood-Fired_Pizza_Oven_Owners_Manual_2.pdf) — No flames from the mouth or chimney; if it happens, close the door and wait for the fire to die down; never use water on the bricks or to put out the flame; soft and painted wood coat the flue with creosote; [Chicago Brick Oven — CBO-500/750/1000 User Manual](https://cdn.shopify.com/s/files/1/2643/6080/files/CBO_500-750-1000_User_Manual_120225_English_V1_-_Digital.pdf?v=1787951517) — Creosote makes an extremely hot fire when ignited; have a clearly understood plan for a chimney fire and ask the local fire authority; use hardwood dried at least two years; [NFPA — Cooking safety](https://www.nfpa.org/education-and-research/home-fire-safety/cooking) — For an oven fire, turn off the heat and keep the door closed; get out, close the door behind you and call 9-1-1 after you leave Close on smoke curling out of the chimney cap above a pizza oven. ## Smoke rolling into the room or the covered patio EPA's Burn Wise guidance for smoke inside a home is to shut down the wood-burning appliance, open a window, make sure the flue is open and call a professional installer or chimney sweep. For a pizza oven that means no more wood, the door set as the manual allows so the fire burns down, windows and doors opened to the outside, and people who are sensitive to smoke taken out of the room first. EPA names children, older adults and anyone with heart or lung disease, asthma included, as more at risk from wood smoke. If there is a carbon monoxide alarm, it overrides everything else. NFPA says that when a CO alarm sounds, move to fresh air outdoors or by an open window or door, make sure everyone is accounted for, and call for help from that fresh-air spot. ### In a pizzeria when the exhaust fan stops Marra Forni's manual for its commercial wood ovens says the exhaust hood and makeup-air blowers must run whenever the oven is fired, and that if the hood's power ventilator fails, the oven door should be closed to put the fire out and keep heat from building in the duct, where it can set off the suppression system. Middleby Marshall's gas conveyors are built to run only under powered, air-sensed ventilation. A dead fan is a stop-the-oven event, not a reason to prop the back door open and keep baking. Source: [NFPA — Carbon monoxide safety](https://www.nfpa.org/education-and-research/home-fire-safety/carbon-monoxide) — If the CO alarm sounds, move to fresh air outdoors or by an open window or door, account for everyone and call for help from there; [EPA Burn Wise — Wood-burning installation and maintenance](https://www.epa.gov/burnwise/wood-burning-installation-and-maintenance) — If you smell smoke in the home, shut down the appliance, open a window, make sure the flue is open and call a professional installer or chimney sweep; chimney cracks can let smoke in and expose parts to high temperatures; [EPA Burn Wise — Wood smoke and your health](https://www.epa.gov/burnwise/wood-smoke-and-your-health) — Children, older adults and people with heart or lung disease, including asthma, are at greater risk from wood smoke ## Where the fuel for a flue fire comes from Alfa and Chicago Brick Oven describe the same process: wood burned slowly gives off tar and organic vapors that mix with moisture from the wood, condense on the cooler walls of the flue and build up as creosote. Wet wood, soft wood and long smoldering fires feed it fastest. Coyote warns that pine, fir, cedar, painted wood and plywood coat the oven and the flue with creosote, and Chicago Brick Oven asks for hardwood dried at least two years. How often the flue needs attention depends on use. Alfa asks home owners to inspect the chimney for creosote at least twice a year and to sweep it once a year, partly because nesting birds can block it. Marra Forni asks restaurants to inspect the flue, the exhaust duct and the power ventilator at least twice a month and to hire experienced duct-cleaning crews to remove creosote and grease. Source: [Coyote — Duomo Wood Fired Pizza Oven Owner's Manual](https://coyoteoutdoor.cdn.prismic.io/coyoteoutdoor/aBI1GfIqRLdaBwbi_Coyote_Wood-Fired_Pizza_Oven_Owners_Manual_2.pdf) — No flames from the mouth or chimney; if it happens, close the door and wait for the fire to die down; never use water on the bricks or to put out the flame; soft and painted wood coat the flue with creosote; [Alfa Forni — User manual, domestic ovens (North America)](https://www.alfaforni.com/download/user-manual/home/user_manual_domestic_ovens-NA.pdf) — Never use so much wood that flames exit the chimney cap; slow burning forms creosote in the flue; inspect for creosote at least twice a year and sweep the flue once a year; [Chicago Brick Oven — CBO-500/750/1000 User Manual](https://cdn.shopify.com/s/files/1/2643/6080/files/CBO_500-750-1000_User_Manual_120225_English_V1_-_Digital.pdf?v=1787951517) — Creosote makes an extremely hot fire when ignited; have a clearly understood plan for a chimney fire and ask the local fire authority; use hardwood dried at least two years; [Marra Forni — Static oven manual (Rev. 5-2026)](https://marraforni.com/wp/wp-content/uploads/2026/05/Static-Manual-Marra-Forni-Rev-5-2026.pdf) — Hood and makeup-air blowers must run whenever the oven is fired; if the power ventilator fails, close the oven door to extinguish the fire; inspect flue, duct and ventilator at least twice monthly ## After the fire, before the next bake A chimney fire can crack a clay or masonry liner, separate pipe joints, buckle a rain cap and scorch framing where the flue passes a roof or wall. EPA notes that chimney cracks can let smoke into the home and expose surrounding parts to temperatures high enough to start a fire. Most of that damage cannot be seen from the patio, so the oven stays cold until someone qualified has looked at the whole run. What you can do from the ground is gather details for the visit: photos of the cap and the outside of the pipe, a note of how long the roar lasted, what wood was burned that night and when the flue was last swept. - The flue lining and every pipe joint, from the oven collar to the cap - The rain cap and spark screen, often clogged with soot flakes - Clearances where the pipe passes a roof, pergola or wall - The dome and floor near the flue opening for new cracks - On commercial ovens, the hood, the duct and the fan Source: [EPA Burn Wise — Wood-burning installation and maintenance](https://www.epa.gov/burnwise/wood-burning-installation-and-maintenance) — If you smell smoke in the home, shut down the appliance, open a window, make sure the flue is open and call a professional installer or chimney sweep; chimney cracks can let smoke in and expose parts to high temperatures; [USFA — Heating fire safety](https://www.usfa.fema.gov/prevention/home-fires/prevent-fires/heating/) — Have heating equipment and chimneys cleaned and inspected each year by a professional ## Where to stop Nobody climbs to the chimney cap, pulls pipe sections apart or runs a brush up a flue that has just burned. The oven stays unlit until the flue, liner, cap and nearby framing have been inspected, and on a commercial oven until the hood and duct have been cleaned by an exhaust crew. Written by [PizzaOvenRepair.center technical team](https://pizzaovenrepair.center/authors/technical-team/). Technicians servicing backyard pizza ovens and pizzeria deck and conveyor ovens, drawing on field visits and oven manuals. Sources: [Coyote — Duomo Wood Fired Pizza Oven Owner's Manual](https://coyoteoutdoor.cdn.prismic.io/coyoteoutdoor/aBI1GfIqRLdaBwbi_Coyote_Wood-Fired_Pizza_Oven_Owners_Manual_2.pdf) · [Alfa Forni — User manual, domestic ovens (North America)](https://www.alfaforni.com/download/user-manual/home/user_manual_domestic_ovens-NA.pdf) · [Chicago Brick Oven — CBO-500/750/1000 User Manual](https://cdn.shopify.com/s/files/1/2643/6080/files/CBO_500-750-1000_User_Manual_120225_English_V1_-_Digital.pdf?v=1787951517) · [Marra Forni — Static oven manual (Rev. 5-2026)](https://marraforni.com/wp/wp-content/uploads/2026/05/Static-Manual-Marra-Forni-Rev-5-2026.pdf) · [Middleby Marshall — PS638 Series Owner's Operating and Installation Manual](https://www.middlebymarshall.com/wp-content/uploads/2021/07/74617-PS638-Owners-Manual.pdf) · [NFPA — Cooking safety](https://www.nfpa.org/education-and-research/home-fire-safety/cooking) · [NFPA — Carbon monoxide safety](https://www.nfpa.org/education-and-research/home-fire-safety/carbon-monoxide) · [EPA Burn Wise — Wood-burning installation and maintenance](https://www.epa.gov/burnwise/wood-burning-installation-and-maintenance) · [EPA Burn Wise — Wood smoke and your health](https://www.epa.gov/burnwise/wood-smoke-and-your-health) · [USFA — Heating fire safety](https://www.usfa.fema.gov/prevention/home-fires/prevent-fires/heating/) ## Step by step. Five steps, in the order worth doing them. 01 ### Stop adding wood Put nothing more on the fire and step back from the mouth and the pipe. 02 ### Close the door Close the pizza oven door, or set it as the manual allows, so the fire runs short of air. 03 ### Shut the gas On a hybrid or gas oven, turn the burner off and close the supply valve if you can reach it safely. 04 ### Clear the area Move guests and pets well away, and open windows if smoke is inside a room. 05 ### Call 911 if it spreads Call from a safe spot when flame shows at the cap or anything nearby catches. For the heart of your home. ## Questions owners ask. ### Can I let a small pizza oven chimney fire burn itself out? Only with the door closed, the gas off, people back and someone watching the cap and roof from a distance. If flame leaves the cap or sparks land on anything, call 911. ### Why did smoke come out of the mouth instead of the chimney? The flue was not drawing: wet wood, a cold oven, a blocked cap, a short pipe or wind pushing down. EPA also suggests opening the door slowly when loading to cut spillage. ### Do chimney cleaning logs replace a sweep? The pizza oven makers do not name them. Alfa, Chicago Brick Oven and Marra Forni call for inspection and removal of the buildup, and USFA asks for yearly professional cleaning. ### Is soot on the front of the dome a warning sign? Often. Black streaks above the mouth show smoke leaving the front instead of the flue, the same weak draft that leaves creosote in the pipe. ## The problems behind it. Each has a page of its own: what it usually means and the causes in the order worth checking. [All 17 problems](https://pizzaovenrepair.center/problems/) Gas, fire or smoke at the oven ### Flames Rolling Out of the Pizza Oven Mouth or Chimney 6 causes, cheapest first Gas, fire or smoke at the oven ### Pizza Oven Smoke Filling the Room Instead of Leaving by the Flue 6 causes, cheapest first Problem ### Wood-Fired Pizza Oven Smoking Heavily Out of the Chimney Top 6 causes, cheapest first Problem ### Black Soot Streaks on the Pizza Oven Arch and Front Face 6 causes, cheapest first ## When it needs a technician. The repairs on the right are where this guide ends when the checks do not settle it. ### Pizza oven door and chimney repair Pizza oven doors, hinges, springs, gaskets and heat shields repaired, and chimneys cleaned, capped and set to draw, so heat stays in and smoke goes up. ### Pizza oven cleaning and safety inspection A full cleaning of the pizza oven's burners, floor, fingers, chimney path and vents, with a gas leak check, flame check and written safety report. ### Pizza oven blower and fan repair Impingement blowers, cooling fans, bearings, belts and air fingers repaired or replaced, so hot air reaches every lane of the pizza oven evenly. ## More in gas, fire, smoke and food. What to do about a gas smell at the pizza oven, fire escaping the mouth or burning in the chimney, smoke filling the room, and how hot toppings must get before a pie is safe to serve. [The whole section](https://pizzaovenrepair.center/guides/safety-and-food/) Gas, flame, smoke and safe bake temperatures ### A gas smell at the pizza oven: burners off, supply closed, everyone back Why a working oven can still leak, the four moves the makers print for outdoor ovens, the stricter rules inside a pizzeria, and what has to happen before anyone lights it again. Gas, flame, smoke and safe bake temperatures ### Burning the right wood in a pizza oven: dry hardwood, under 20 percent How to tell seasoned wood by color, weight and sound, the hardwoods the makers name, what never goes on the fire, where to stack it, and how wet wood shows up as smoke and soot. Guides ### All 18 guides Six sections, by what you are trying to find out. --- **[Read on the site: Chimney fire or smoke in the room: closing the door on a pizza oven flue](https://pizzaovenrepair.center/guides/a-chimney-fire-or-smoke-in-the-room/)** **[Book a visit with PizzaOvenRepair.center](https://pizzaovenrepair.center/schedule/)**