Osburn Matrix 2700 Wood Insert

The Osburn Matrix 2700 Wood Insert is an EPA 2020 certified wood insert for 750 to 2,200 sq ft. It burns up to 8 hours on a load and takes a 6-inch (insert liner) chimney.

Who it's for

Right buyer. Owners of a working masonry fireplace with a large opening who want to convert an inefficient open hearth into a serious primary heat source — up to 2,200 sq ft of zone heating capability with a 2.5 ft³ firebox, 20-inch log capacity, and an 8-hour maximum burn cycle.

Buyers heating 1,500–2,000 sq ft as primary winter heat in moderate climates, or 1,200–1,500 sq ft in cold climates and older homes.

How it performs

The 80,000 BTU/hr maximum is a peak rating, transient, achieved on dry cordwood at high loading density and short reload intervals. It is real, but it is a peak rating, not the average output across a full burn cycle of normal operation.

Good to know

• Large appliance, large masonry opening required. The 2700's minimum opening of 27 1/8" H × 31 3/4" W × 22 1/8" D is substantial.
• Efficiency is lower than smaller siblings. 64% HHV is lower than the 68% HHV on the Osburn 1700-I and 71% HHV on the 3500-I.
• Low published emissions is the headline.

Dimensions

Minimum fireplace opening

Measure the inside of the firebox: width, height and depth. The insert needs at least this much, and the faceplate covers the rest of the old opening.

Dimensions from the specification sheet

Dimensions

Where it can go

The Matrix 2700 is approved only for installation inside an existing code-compliant masonry fireplace with a continuous stainless-steel chimney liner. It is not approved for installation in factory-built (prefab) metal fireplaces, in mobile or manufactured homes, in alcoves, or as a freestanding unit. The masonry fireplace and chimney must be inspected before installation for cracks, loose mortar, creosote, blockage, or other signs of deterioration.

Clearances to combustibles

Floor protection

Floor protection requirements depend on whether the projection kit is installed and whether the existing masonry hearth is raised above the surrounding combustible floor. Without the projection kit, the manual requires a non-combustible floor protector extending at least 18 inches in front of the unit in Canada or 16 inches in the USA, measured from the door opening. If the masonry hearth is level with or only slightly raised above the surrounding combustible floor, an R-value floor protector may be required per the manual's floor-protection worksheet.

With the projection kit installed, the forward extension threshold increases. The manual includes a thermal-resistance lookup table for common floor protection materials (brick, cement board, ceramic tile, marble) to calculate the required R-value combination. Tile alone is not sufficient — the manual requires a continuous non-combustible sheet beneath any tile installation. Final hearth protection must be calculated from the manual's floor-protection worksheet and approved by the installer/AHJ.

Clearances

United States figures, in inches. The rating plate on the appliance overrides any published number; the installer confirms on site.

Documents

• Osburn Matrix 2700 wood insert install & owner's manual (PDF - 7.7 MB)
• Osburn Matrix 2700 Dimensions (PDF - 1.1 MB)
• Installation instructions | Cuttable faceplate | Projection kit (PDF - 1.1 MB)
• Maximum recommended heating area by climate zone (PDF)
• Osburn wood products brochure, USA edition, with dimension drawings (PDF)
• Osburn limited lifetime warranty
• EPA test reports
• Replacement parts

Details

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 insert 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, and blower 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.

Heat

From the specification sheet

Choices and prices

Options

The unit price is Osburn's 2026 list price for the wood insert 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

What arrives

• Osburn Matrix 2700 wood insert (OB02700) with welded carbon-steel firebox and cast-iron glazed door
• Standard cast-iron faceplate (30 1/8" × 43 5/8")
• Configured at order with required door overlay selection — see "Where it can go" for the options
• 176 CFM heat-activated double-cage blower assembly with rheostat speed control and three-position switch (AUTO / OFF / MANUAL)
• C-Cast baffle and stainless-steel secondary-air tube assembly
• Moulded refractory bricks lining (floor, sides, back)
• Adjustable threaded legs
• Removable air-control handle
• Liner fixation brackets and hardware
• Owner's manual and product documentation

Sold separately

• 6-inch continuous stainless-steel chimney liner kit (UL 1777, CAN/ULC-S635, or CAN/ULC-S640) — required for installation, sized to the chimney height
• Hearth extension or floor protector sized per manual specifications, extending at least 16 inches in front of the unit in the USA, 18 inches in Canada
• Sheet-metal block-off plate, high-temp silicone, and mineral wool insulation — effectively required in practice for the insert to deliver rated performance
• Optional projection kit, 2" or 4" (SBI AC01263) — for installations where the fireplace depth is less than the 22 1/8" minimum
• Optional 34" × 50" cuttable faceplate, 18 GA (SBI AC01277) — for masonry openings larger than the standard faceplate covers
• Optional 5-inch fresh-air intake kit (SBI AC01298) — for code jurisdictions requiring outside combustion air or for tight new-construction homes
• Optional 5-inch × 4' insulated flex pipe for fresh-air intake (SBI AC02090) — HVAC type, ULC S110 or UL 181 class 0 or class 1
• Optional firescreen door (SBI AC01275) — for occasional attended fire viewing only where permitted by local code and only when used exactly as instructed in the fire screen manual; never leave the insert unattended when used with a fire screen
• Optional liner hook-up system (SBI AC02006) — simplifies liner-to-flue-collar connection
• Optional offset liner adapter (SBI AC01214) — for installations where the chimney throat geometry requires offset connection
• Optional tempered glass hearth pad 10mm 18" × 50" (SBI AC02760)
• Pin-type wood moisture meter — not optional in practice
• Flue thermometer — strongly recommended for insert installations since stove-top temperature isn't accessible
• Installation by an authorized qualified technician (WETT, NFI, or CSIA certified) — required for warranty coverage and often required by code, permit, or insurance

Installation

Chimney requirements from the specification sheet

The Matrix 2700 requires a continuous 6-inch stainless-steel chimney liner extending from the insert flue collar to the top of the chimney. The liner must conform to ULC S635, CAN/ULC-S640 (Canada) or UL 1777 (USA) and be rated for solid fuel. The minimum liner 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.

The Matrix 2700 performs best with a 6-inch stainless-steel chimney liner. In the USA, use a 6-inch liner listed to UL 1777. In Canada only, connection to a chimney liner of at least 5 inches may be permitted if it properly vents combustion gases, the total masonry chimney height is greater than 20 feet, and the application is verified and authorized by a qualified installer. The insert is not approved for a positive flue connection to clay tile — a continuous stainless liner is required.

If the existing fireplace's throat damper is to remain, it must be locked open to clear the liner; otherwise the damper plate must be removed. A sheet-metal block-off plate sealed at the damper level (or, in Canada per CSA B365, mineral wool packing around the liner) is recommended at the throat to reduce cold-air backdraft and to allow the insert to deliver rated performance — without it, jacket-recovered heat is lost into the smoke chamber. An insulated liner (or pre-insulated liner with a wrap) improves draft and reduces creosote, and is required by code in some jurisdictions for clearance reasons.

Outside air

An optional fresh-air intake kit is available for code jurisdictions requiring outside combustion air or for tight new-construction homes with mechanical ventilation. In conventional homes the manual identifies room air as the safest and most reliable supply for combustion; almost all houses have enough natural leakage to provide what the insert needs. A smoke detector and carbon monoxide detector are required in the room where the insert is installed.

Codes and approvals

Code compliance for any specific installation is determined by the local Authority Having Jurisdiction. Manufacturer listings cover what the insert 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. In Canada the CSA B365 standard applies; in the USA, ANSI NFPA 211 applies. 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.

Planning the install

• 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.