Osburn Everest III Wood Fireplace

The 21-inch combustible side-wall clearance is meaningfully larger than the 13-inch side-wall clearance on the Solution 2.5 ZC II and other smaller SBI fireplaces — this fireplace needs more lateral wall framing space. Verify chase width with your installer before committing.

Clearances apply identically in Canada and the USA per the manufacturer's clearance table. The certification label on the unit is the binding clearance for any installation and always overrides clearance figures published in any other media. Some appliances have been tested with a low ceiling — refer to the installation manual for reduced-ceiling configurations. Confirm the binding clearance figures with your installer before purchase.

From the specification sheet

Options

The unit price is Osburn's 2026 list price for the wood fireplace alone. Options sold on this page add to it; those marked on request we add to your order by hand.

Door overlay

Faceplate and trim

Fresh air

Other options

Chimney requirements from the specification sheet

A 6-inch chimney flue system is required. New factory-built chimney systems must comply with UL 103 HT (USA) or ULC S629 (Canada) and be suitable for solid fuel. Approved manufacturer/brand combinations listed by SBI include American Metal HSS and HS, DuraVent Dura Tech / Dura Tech Premium / Dura Plus HTC / Dura Plus, Metal Fab Temp Guard, Olympia Champion and Rockford, Ventis (Olympia/SBI Venting Division), Nexvent (SBI Venting Division), Security Chimney ASHT and S-2100, and Selkirk Ultimate Plus / CF Sentinel / Super Pro 2100 / Super Vent 2100. Verify the chimney brand and component series with your installer before ordering venting.

The minimum chimney height is 15 feet, subject to installer verification, certification label, draft conditions, and local code. The chimney must extend at least 3 feet above the highest point of contact with the roof and at least 2 feet above any roof line or obstacle within 10 feet horizontally.

Outside air

Outside air is not required in conventional homes — combustion air is normally available from room air. However, the optional fresh-air intake register (SBI AC01347, 4-inch) and 4-inch × 10-foot insulated flex pipe (SBI AC02091) are strongly recommended for tight new-construction homes with mechanical ventilation, for homes with powerful range hoods or other mechanical exhaust appliances, and where local code requires it. A smoke detector and carbon monoxide detector are required in the room where the fireplace is installed.

Codes and approvals

Code compliance for any specific installation is determined by the local Authority Having Jurisdiction. Manufacturer listings cover what the fireplace is approved for; the AHJ approves what is permitted at your address. A WETT (Canada), NFI, or CSIA (USA) certified installer is strongly recommended and frequently required by code, permit, or insurance. Zero-clearance wood-burning fireplaces are a regulated category — confirm local requirements before purchasing, particularly in EPA non-attainment counties and in HOA jurisdictions where new wood-burning installs may be restricted.

California Proposition 65

This product can expose you to chemicals including carbon monoxide, which is known to the State of California to cause cancer, birth defects or other reproductive harm. For more information go to www.P65warnings.ca.gov.

• Everest III zero-clearance fireplace with welded steel firebox, retractable cast-iron double doors, moulded refractory brick lining, stainless-steel secondary-air system, and listed insulation, shielding, and standoffs that allow installation inside a framed combustible chase per the manual's required clearances, framing dimensions, air spaces, and finish-material zones
• Configured at order with required faceplate selection — Traditional Faceplate (default) or Modern Faceplate (upgrade)
• Configured at order with required door overlay selection — Black Door Overlay (default) or Brushed Nickel Door Overlay (upgrade)
• 176 CFM blower with rheostat speed control
• C-Cast baffle
• Owner's installation and operation manual and product documentation

Sold separately

• Code-compliant 6-inch Class A insulated chimney system — listed factory-built chimney from an approved manufacturer/brand per the manufacturer's approved-chimney list; required venting components are sold separately
• Hearth extension or floor protection sized to manual specifications, with continuous non-combustible material in front of the fireplace
• Optional Forced Air Kit (SBI VA4460) — distributes heat to a remote room via insulated ducting; includes 6" × 25' insulated flex pipe (SBI AC01350); use only manufacturer-supplied components
• Optional Firescreen Door (SBI AC01226) — for occasional attended fire viewing only with the retractable doors open, where permitted by local code and only when used exactly as instructed in the firescreen manual; never leave the fireplace unattended when used with a firescreen. Open-door operation with a firescreen is prohibited in the United States and in Canadian provinces with particulate emission limits
• Optional NightFlame Semi-Transparent Black Glass set of 2 (SBI AC02776) — ROBAX® ceramic glass upgrade that conceals the firebox interior when the fire is out and reveals the flames when burning
• Optional Traditional Gravity Kit (SBI AC01375) — for installations where finish material extends to the edge of the door without visible louvers, traditional style
• Optional 4-inch fresh-air intake register with airtight damper (SBI AC01347) — closable outside-air damper for tight homes or where local code requires it; do not close while the fireplace is in use
• Optional 4-inch × 10' insulated flex pipe for fresh air intake (SBI AC02091)
• Optional Fireplace Carrying Handles (SBI AC09200) — site handling aid during installation; not part of the finished assembly
• Digital moisture reader and probe thermometer — strongly recommended; not optional in practice
• Installation by an authorized qualified technician (WETT, NFI, or CSIA certified) and a framing contractor familiar with zero-clearance fireplace chase construction — required for warranty coverage and often required by code, permit, or insurance

• Check with your building department and insurer: wood appliances need a permit in most places and an inspection after installation.
• The chimney is the other half of the system. It is sold separately and quoted from your installer's plan.
• Clearances and floor protection come from the manual and depend on the pipe and shields you choose. Send us your plan and we will check it.
• Burn seasoned wood below 20 percent moisture. Wet wood is the cause of most complaints about any wood stove.
• Special-order goods ship by freight.

The 85,000 BTU/hr maximum is a peak rating, transient, achieved on dry cordwood at high loading density and short reload intervals. The figure that matters for daily life is the sustained output across a full burn cycle, which lands in the 25,900–78,200 BTU/hr band per the CSA B415.1-10 stack-loss method.

A realistic operating day, primary-heat use, cold climate: morning reload at sunrise produces a fast 60–90 minute warm-up and several hours of high output; mid-afternoon reload sustains heat through evening; a full pack at bedtime gives 6–7 hours of useful heat overnight, with the fireplace at coals by morning. In practical use with seasoned oak, maple, or hickory, expect 6–8 hours of useful heat from a packed load. With birch, pine, or softer wood, expect 4–5 hours.

The retractable cast-iron double doors are the structural signature of this fireplace. Closed, the doors form a sealed combustion envelope with air-wash glass — this is the standard operating mode and the configuration the EPA 2020 cordwood certification was tested against. The retracted-door mode with the optional firescreen door (SBI AC01226) is prohibited in the United States and in Canadian provinces with particulate emission limits; where the open-fire mode is permitted, it is for attended viewing only and is not the EPA-certified combustion configuration.

The 65% HHV average efficiency is slightly higher than the smaller Stratford II / Solution 2.5 ZC II (64% HHV) — modest improvement from the larger firebox and the heat-transfer geometry of the retractable-door design. The 71.6% optimum at low burn rate is competitive with the larger Horizon / Solution 4.5 ZC.

The 20-inch maximum log capacity is generous for a 3.04 ft³ firebox. Most firewood suppliers cut to 16 inches, which is also the manual's recommended length. The 17-inch firebox depth accepts loading over both width (east-west) and depth (north-south) — north-south loading allows packed overnight cycles with maximum fuel mass.

The included 176 CFM blower meaningfully improves heat distribution into the room and adjacent spaces — the same blower used on the larger Horizon and Solution 4.5 ZC. Air is distributed from behind the firebox out through the louvers.

With the optional Forced Air Kit (SBI VA4460) installed and properly sized, the manufacturer expects at least 25% heat transfer to a remote room — typically a bedroom on the same floor, or an adjacent zone of a great-room layout. The kit takes heat that would otherwise stay in the chase and routes it via 6-inch insulated flex pipe to a wall or ceiling grille in another room. Shorter, straighter runs work best; long or twisty runs cool the combustion chamber and reduce both heat output and combustion quality.

The 1.9 g/hr particulate emissions is below the EPA 2020 cordwood limit of 2.5 g/hr — higher than the 1.2 g/hr Stratford II or 1.6 g/hr Horizon, but still cleanly compliant. The CO emissions figure on the manufacturer page is published as 1.7 g/min (not g/hr like other SBI fireplaces) — if read as g/hr equivalent it's approximately 102 g/hr, in line with the Stratford II's 98 g/hr. Verify the unit with the dealer if the number drives the purchase decision.

Trade-offs to know

Two buyer-configurable choices at order. Faceplate (Traditional default, Modern upgrade) and door overlay (Black default, Brushed Nickel upgrade) are real buyer selections — both with upcharges, neither field-swappable after order. Walk through both choices with the room aesthetic in mind before ordering.

Narrower glass viewing area than smaller siblings. The 18 3/4" × 11" ceramic glass is smaller than the 22 1/4" × 13 1/2" glass on the Solution 2.5 ZC II / Stratford II despite the larger firebox. The retractable-door architecture takes some viewing real estate. If wide flame view is the priority and you don't need the retractable-door architecture, the smaller sibling models offer more glass area.

Larger combustible side-wall clearance. 21 inches of combustible side-wall clearance is meaningfully more than the 13 inches required for the Solution 2.5 ZC II. The chase needs wider lateral framing space — verify the wall depth where the fireplace will be installed before committing to this model.

Lower efficiency than freestanding stoves. A wood fireplace at 65% HHV average efficiency is realistically 5–10 efficiency points lower than freestanding wood stoves of comparable firebox volumes. The architectural integration of a built-in fireplace costs heat — less exposed appliance surface to radiate into the room, more heat lost into the chase. Choose a fireplace for the architectural look and the wall-integrated install; choose a freestanding stove if maximum efficiency per cord of wood is the priority.

Forced air kit is sold separately. While the 176 CFM blower is included, the Forced Air Kit (VA4460) that redirects heat to a remote room is an additional line item. For multi-room or multi-zone heating, plan the kit cost and the chase pre-routing for the 6-inch flex pipe before framing.

Non-catalytic burn time. A non-cat appliance gives you simpler operation and no catalyst to replace, but you pay for it with shorter burns. The 8-hour maximum claim is achievable on a packed load of dense hardwood with the air shut down hard; useful heat through that cycle is realistically 6–7 hours. For 12+ hour overnight burns with steady output, a catalytic or hybrid stove is the right tool.

525 lb shipping weight. Heavy enough to require multi-person handling at delivery; the curb-to-chase move is not a one- or two-person job. Confirm framing load and floor support before installation.

Mobile home approval split by country. Approved for mobile-home installation in Canada per manufacturer listing; NOT approved for mobile-home installation in the United States. US buyers in mobile or manufactured homes need a different appliance category.

Living with it

First burns. The first three to six fires release paint VOCs as the high-temperature stove paint cures. The smell can be strong during paint cure-in. Ventilate the room well, avoid prolonged exposure, and expect the odor to disappear after the first several hot burns.

Lighting. The manual describes top-down lighting as an effective method — largest splits on the bottom, smaller above, kindling on top, fire starter at the very top, light the top. Cleaner ignition, less smoke, faster to operating temperature.

Air control. Full open at light-off, then gradually closed only after the load is fully engaged and stable secondary flames are established. A flue thermometer is strongly recommended — without one, you are guessing at draft, burn rate, and overfire risk. The manual specifies keeping flue temperature in the comfort zone of 250–475 °F at steady state, with 700 °F acceptable transiently during start-up. Do not maintain excessive temperatures over long periods.

Closed-door operation is the standard heating mode. Closed-door operation is the EPA-certified combustion configuration. The doors regulate combustion air through the air-wash glass and form the sealed envelope the certification was tested against. The optional firescreen door (AC01226) is for occasional attended viewing only where local code permits; open-door operation with a firescreen is prohibited in the United States and in Canadian provinces with particulate emission limits. Never leave the fireplace unattended in any operating mode.

Reload cadence. 3–5 hours between reloads in active high-output use; 6–7 hours for a final overnight pack with the air shut hard. Open the air, wait 30 seconds, open the door slowly to avoid spilling smoke into the room. Place at least three pieces on the fire at a time so that the heat radiated from one piece helps ignite the pieces next to it. Normal cordwood loading has no four-log limit — pack the firebox as the loading geometry and burn schedule allow, up to the air-tube level.

Blower management. The blower starts automatically via the included heat sensor when the fireplace reaches operating temperature, typically about an hour after cold start. Turn the rheostat to LO or HI to set speed; the sensor handles on/off. Turn the blower OFF before opening the door fully — otherwise it can blow ash out of the firebox into the room.

Glass cleaning. Damp newspaper dipped in cold ash, or a dedicated ceramic-glass cleaner. Daily wipe during low-burn weather; weekly during high-burn. Black streaks at the lower edge mean wet wood; black uniformly across the glass means burns are running too cool. Do not clean the glass when the fireplace is hot, and do not strike or slam the glass doors shut.

Door alignment and gasket replacement. The door gasket needs replacement when the paper-strip test fails: close the door on a strip of paper and try to pull it out; firm resistance means the gasket is sealing, easy pull means it's time to replace. The double-door design has gaskets on both doors and at the meeting edge — test all locations. Plan on gasket replacement every 3–5 seasons in regular use. Gasket and silicone kits and self-adhesive glass gasket are available through the SBI parts network.

Warranty

A one-time replacement limit applies to all parts with lifetime coverage. Warranty is void if the unit is used to burn anything other than seasoned cordwood, or if it is not operated according to the owner's manual. Damage caused by misuse, improper installation, lack of maintenance, overfiring, downdrafts, venting problems, or under-estimated heating area is not covered. Improper installation by anyone other than an authorized qualified technician voids the warranty.

Warranty claims are made through your Osburn dealer and remain subject to SBI/Osburn inspection, approval, and the current written warranty. Kaminos is the retailer for this fireplace and supports buyers through purchase; final warranty approval rests with SBI as the manufacturer. SBI's parts network is well-stocked — replacement bricks, baffle, secondary tubes, glass, gaskets, blower, faceplate, door overlay, and venting components are openly available at fair prices through multiple parts vendors.

Osburn may require photos or returned parts to support a claim; repair work covered by warranty requires prior manufacturer approval.

Coverage details can change by component and warranty revision; the current Osburn warranty controls.

• Osburn document list for the Osburn Everest III (OB04017): installation and owner's manual, safety notices
• Osburn wood products brochure, USA edition, with dimension drawings (PDF)
• Osburn limited lifetime warranty
• EPA test reports
• Replacement parts