How To Put Out A Fire In A Chimney: Emergency Suppression & Safety Protocol

To put out an active chimney fire, immediately cut off the appliance oxygen supply by closing all intake air vents, deploy a specialized pyrotechnic chimney fire extinguisher or Class ABC dry chemical powder into the firebox, and evacuate occupants while alerting emergency services via 911. Never throw liquid water directly into a blazing flue, as explosive steam expansion and extreme thermal shock can crack clay or stainless steel liners, releasing 2,000°F flames into surrounding wall framing. Swiftly starving the firebox draft while applying blanket suppressants stabilizes the stack until fire personnel arrive.

Emergency Suppression Preparedness & Equipment Checklist

A chimney fire occurs when highly combustible creosote deposits—accumulated along the inner walls of a flue liner—ignite under high heat. Creosote burns at temperatures ranging from 1,000°F to upwards of 2,000°F (537°C to 1,093°C), far exceeding the structural design limits of residential masonry and factory-built chimneys specified under National Fire Protection Association (NFPA) 211 standards.

When a chimney fire ignites, time is the critical variable. Having the correct suppression tools pre-staged near the hearth allows home occupants to act decisively within the first 60 to 120 seconds of ignition, preventing structural heat transfer into attic framing and roof trusses.

Suppression Gear & Tool Kit

• Specialized Chimney Fire Extinguisher: One or two pyrotechnic chimney fire suppression sticks (such as Chimfex). These produce an oxygen-starving, dense smoke cloud when ignited in the firebox.
• Class ABC Dry Chemical Extinguisher: A minimum 5 lb monoammonium phosphate fire extinguisher rated for Class A (wood), B (liquids), and C (electrical) fires.
• Heavy Heat-Resistant Gloves: Heavy-duty leather welding gloves or NFPA-compliant turnout gloves rated for temperatures above 500°F.
• Fireplace Tool Set: Heavy iron poker, metal shovel, and tongs to manipulate burning logs safely.
• Covering Material / Sealant: A thick sheet of heavy-gauge sheet metal or a dedicated steel hearth cover to seal the firebox opening if glass doors are absent.
• Outdoor Garden Hose: Staged outdoors, fully uncoiled, connected to an active water source, equipped with an adjustable spray nozzle set to fine mist.

Prerequisite Safety Standards & Operational Metrics

• NFPA 211 Compliance Awareness: Familiarity with chimney clearances (combustibles must remain a minimum of 2 inches away from exterior chimney masonry and 18 inches from uninsulated single-wall stove pipes).
• Primary Air Control Location: Precise knowledge of how to operate the primary and secondary air intake dampers on wood stoves or insert appliances under zero-visibility conditions.
• Estimated Budget for Emergency Safety Kit: $45 – $130 for complete firebox suppression equipment (suppressant stick, dry chemical extinguisher, and thermal gloves).
• Target Response Duration: 0 to 3 minutes for firebox isolation and chemical deployment; 3 to 15 minutes for emergency department arrival.

Step-by-Step Chimney Fire Suppression Protocol

Step 1: Alert Emergency Services and Initiate Household Evacuation

The moment a chimney fire is detected—characterized by a loud roaring or freight-train noise, intense vibrations in the stovepipe, or dense black smoke shooting from the roof stack—immediately direct all occupants to evacuate the building. Dial 911 from a mobile phone or a neighbor's house.

Warning: Never assume a chimney fire will burn itself out. Creosote fires can instantly breach cracked mortar joints or single-wall stovepipes, igniting structural wall studs inside attic spaces before visible flames appear outside.

Step 2: Restrict Primary Oxygen Supply to the Appliance

Fire requires fuel, heat, and oxygen. In a chimney fire, the flue acts as a high-velocity engine drawing massive volumes of air through the firebox. Immediately choke off this air supply:

1. If operating a wood stove or pellet stove, completely close the primary air intake controls, spin draft controls shut, and close any secondary air dampers.
2. If operating an open fireplace with glass doors, close the glass doors tightly and shut the lower air vents on the frame.
3. Do not completely close the chimney flue damper if doing so causes thick, toxic carbon monoxide and smoke to back-draft directly into the living room. However, if using an insert, throttling the draft valve down limits oxygen intake while maintaining negative pressure inside the pipe.

Pro-Tip: If using an open fireplace without glass doors, place a non-combustible barrier—such as a heavy piece of sheet metal or a fire-rated blanket—directly across the opening to block air intake.

Step 3: Deploy a Specialized Chimney Fire Extinguisher Stick

If safe to approach the hearth while wearing thermal gloves, deploy a specialized pyrotechnic chimney fire extinguisher (e.g., Chimfex):

1. Remove the cap to expose the strike surface.
2. Scratch the strike top against the igniter tip, similar to lighting a road flare.
3. Place the burning stick inside the firebox beside or behind the active wood fire, not directly on top of massive burning logs where it might be smothered.
4. Immediately close the stove door or fireplace glass.

The device releases dense, chemical fumes that absorb oxygen and break the chain reaction of combustion as the draft pulls the gas upwards into the flue liner, smothering the creosote fire within 22 seconds.

Step 4: Alternative Suppression Using Class ABC Dry Chemical Extinguishers

If a specialized pyrotechnic stick is unavailable, utilize a standard Class ABC dry chemical fire extinguisher:

1. Stand 6 to 8 feet away from the hearth, wearing heat-resistant gloves.
2. Aim the nozzle into the firebox, pointing sweeping bursts at the base of the firebox fire, not directly up into the chimney stack.
3. The upward thermal draft will naturally pull the fine monoammonium phosphate powder up into the flue, coating the burning creosote and smothering the flames.

Warning: Do not spray a high-pressure stream directly up into the chimney flue pipe. The blast can bounce off the pipe walls, blowing hot ash, burning creosote flakes, and dangerous chemical dust back into your face and living area.

Step 5: Cool the Primary Fuel Bed (Without Thermal Shock)

If small embers remain burning in the firebox after chemical deployment, sprinkle a light mist of water over the burning wood using a spray bottle, or smother the logs with dry sand, baking soda, or sodium bicarbonate.

Warning: NEVER pour a bucket of liquid water directly into a hot firebox or flue. Converting 1 gallon of liquid water into steam creates over 1,600 gallons of steam instantaneously. This explosive volumetric expansion can cause steam burns, blast hot ash across the room, and trigger extreme thermal shock that shatters clay flue tiles or ruptures stainless steel liner welds.

Step 6: Cool Exterior Roof Hazards and Monitor Internal Heat Transfer

While awaiting the fire department, take outer defensive measures if it is safe to step outdoors:

1. Use an outdoor garden hose set to a wide spray pattern to wet down asphalt shingles, wooden shake roofs, and surrounding tree branches near the top of the chimney stack to prevent stray sparks from igniting the roof.
2. Do not spray water down inside the top of the chimney stack unless explicitly directed by fire personnel, as this will shatter the upper flue lining.
3. Touch interior drywall surfaces along the path of the chimney (in adjacent rooms, closets, and attic spaces) with the back of your hand. If a wall feels dangerously hot to the touch, structural ignition may be occurring behind the drywall; evacuate the property immediately.

Chimney Fire Extinguishment Media & Thermal Specs

Choosing the correct fire suppression medium determines whether a flue fire is successfully contained or escalates into a catastrophic house fire. The table below outlines technical metrics and hazard parameters for standard emergency suppression methods.

Critical Complications & Field Mitigation Strategies

Scenario 1: Intense Smoke and Carbon Monoxide Back-Drafting into Living Space

• Root Cause: The primary air intake was restricted while the flue damper was accidentally closed or choked by falling, collapsing creosote scabs, forcing smoke out through firebox seams.
• Actionable Fix: Do not fully open the damper, as this feeds oxygen to the flue fire. Instead, keep air intakes restricted, crack a window in the room opposite the fireplace to prevent negative pressure draw, and immediately deploy a Chimfex stick or Class ABC extinguisher into the firebox. Seal the glass doors tightly or clamp a metal sheet over the hearth opening to force all emissions up the stack while smothering the combustion base.

Scenario 2: Thermal Shock Crack in Clay Flue Tile During Fire

• Root Cause: Rapid temperature spikes exceeding 2,000°F caused uneven expansion across clay tile walls, or liquid water was mistakenly introduced into the hot flue, causing sudden ceramic fracture.
• Actionable Fix: Immediately cease all water use near the hearth. Transition exclusively to dry powder (ABC extinguisher) or pyrotechnic oxygen-starving sticks. Inform arriving fire crews immediately that the flue liner is compromised, prompting them to check attic spaces and wall cavities with thermal imaging cameras for structural heat transfer.

Scenario 3: Secondary Ignition of Stage-3 Glazed Creosote in the Attic Zone

• Root Cause: Stage-3 creosote forms a dense, shiny, tar-like run down the inner flue lining that burns with high caloric output. Radiant heat penetrates thin brickwork or uninsulated double-wall metal chimneys, setting fire to wood roof framing.
• Actionable Fix: Evacuate all occupants from the upper floors immediately. If trained and safe to do so before fire personnel arrive, discharge a Class ABC extinguisher directly at the junction where the chimney pipe passes through the ceiling joists or roof deck in the attic. Do not enter an attic space if dense smoke is present.

Scenario 4: Melted or Jammed Fireplace Damper

• Root Cause: Extreme thermal expansion or direct flame contact warps cast-iron or steel damper plates, welding them in an open or partially closed state.
• Actionable Fix: Do not spend time attempting to force a jammed damper handle with tools. Shift focus entirely to sealing the lower intake vents and the front face of the firebox. Use a heavy hearth cover plate, wet canvas fire-retardant blanket, or metal shield held tight against the fireplace surround to choke off room-level airflow from reaching the stack.

Frequently Asked Questions

Can I put out a chimney fire by throwing water on it?

No, you should never pour or throw buckets of water directly onto a chimney fire or into a burning firebox. Liquid water exposed to extreme flue temperatures turns instantly into steam, expanding 1,600 times in volume, which can cause steam explosions, blow hot creosote into the living space, and crack flue tiles due to severe thermal shock.

What does a chimney fire sound and look like?

A chimney fire usually makes a loud roaring, rumbling, or rushing sound similar to a low-flying freight train or a jet engine. From the outside of the home, you will see thick, dense black smoke or intense flames and bright sparks shooting out from the top of the roof stack.

Will a chimney fire burn itself out safely without intervention?

No, a chimney fire should never be left to burn itself out. Creosote fires routinely reach temperatures over 2,000°F, which easily melt metal stovepipes, shatter clay liners, and ignite surrounding wooden studs, trusses, and roof decking within minutes.

What causes creosote to build up in a chimney?

Creosote builds up when wood smoke cools as it rises up the flue, condensing water, tar, and unburned hydrocarbons onto the flue walls. Common causes include burning unseasoned or wet wood (moisture content above 20%), smoldering fires caused by choked air intakes, and using an oversized chimney flue.

Can I use my fireplace again after a chimney fire has been put out?

No, you must not use your fireplace or wood stove after a chimney fire until it has been thoroughly inspected and swept by a CSIA-certified (Chimney Safety Institute of America) chimney sweep. The high heat of a chimney fire almost always causes hidden structural damage, such as cracked tiles, warped pipes, or compromised mortar joints, rendering the system unsafe.

Schedule a Professional Post-Fire Chimney Inspection

If your home has experienced a chimney fire, do not light another fire under any circumstances until a full level 2 or level 3 inspection has been performed. Contact a Certified Chimney Sweep to evaluate flue integrity, replace damaged liners, and ensure your heating appliance is safe for operation.