Osburn 1700-I Wood Insert

Right buyer

Owners of a working masonry fireplace with a medium-sized opening who want to convert an inefficient open hearth into a serious primary heat source — up to 1,800 sq ft of zone heating capability with a 1.86 ft³ firebox, 18-inch log capacity, and a 7-hour maximum burn cycle. Reasonable insulation, access to seasoned hardwood at 15–20% moisture, and an existing masonry fireplace that meets the minimum opening dimensions (21 1/2" H × 27 1/2" W × 12 7/8" D per manual) are the basic requirements.

Buyers heating 1,200–1,600 sq ft in moderate climates. The Osburn 1700-I is the medium-sized insert in the Osburn line — bigger than the smaller Osburn 950 and smaller than the Osburn Matrix Insert and Osburn 3500 Insert. For homes in the medium range, it's the right size firebox to deliver real primary winter heat without overheating the space.

Buyers who want the Osburn-tier aesthetic at the medium-insert size. The 1700-I shares its mechanical platform with the Enerzone Solution 1.7-I (same firebox, same blower, same efficiency, same emissions, same burn cycle) but ships with the configurable cast-iron door overlay in Black or Brushed Nickel — a customization layer the Enerzone version doesn't offer.

Buyers who want a customizable Osburn aesthetic. The arched cast-iron door accepts a configurable door overlay in Black or Brushed Nickel, paired with a matching faceplate (Regular or Large) and trim in the same finish.

Wrong buyer

Not for buyers without an existing code-compliant masonry fireplace. Wood inserts must be installed inside a lined masonry fireplace with a continuous stainless-steel chimney liner running the full height. This insert is not approved for factory-built (prefab) metal fireplaces, mobile homes, or any installation outside a masonry hearth.

Not for buyers needing to heat more than 1,800 sq ft as primary winter heat. For larger spaces, step up to the Osburn Matrix Insert (75,000 BTU, larger firebox) or the Osburn 3500 Insert.

Not for buyers expecting 10+ hour overnight burns. The 7-hour manufacturer maximum is achievable on a packed load of dense hardwood with the air shut down hard, but useful heat from a packed load is realistically 5–6 hours. For longer burns, step up a firebox size or consider catalytic technology.

The Osburn 1700-I 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.

Minimum masonry opening

If a fresh-air intake is being installed, add at least 4 inches to the width. Plan for a small installation margin above the insert to seat the liner adapter — an opening exactly at the minimum will be a tight install. Measure carefully before ordering.

Faceplate options

Trim color matches the faceplate finish. The cast-iron door overlay is selected separately in Black or Brushed Nickel — most buyers match both. Selected at order, not field-swappable.

Clearances to combustibles

Reduced clearances are not available by means of heat shields on this insert — the figures above are the binding minimums.

Floor protection

Floor protection requirements depend on whether the existing masonry hearth is raised 4 inches or more above the surrounding combustible floor. If the hearth is raised 4 inches or more, a non-combustible floor protector with no R-value is required and must extend at least 16 inches in front of the unit in the USA, 18 inches in Canada. If the hearth is raised less than 4 inches, a non-combustible floor protector with an R-value of at least 1.00 is required and must extend at least 22 inches in front of the unit. 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.

Chimney and liner

The Osburn 1700-I 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 or 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.

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 (or, in Canada per CSA B365, mineral wool packing around the liner) is recommended at the throat to reduce cold-air backdraft into the room. 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. The fresh-air intake adapter installs on either the left or right side of the insert (the unused side is covered by a plate supplied in the owner's manual kit). A smoke detector and carbon monoxide detector are required in the room where the insert is installed.

Code compliance

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.

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.

Ships with the insert

• Osburn 1700-I wood insert (OB01705) with welded carbon-steel firebox and arched cast-iron glazed door
• Configured at order with required door overlay and faceplate/trim selections — see "Where it can go" for the options
• 144 CFM heat-activated double-cage blower assembly with rheostat speed control and thermodisc auto-on
• Ash lip
• C-Cast baffle and stainless-steel secondary-air tube assembly
• High-density refractory firebrick lining
• 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, with R-value of at least 1.00 if hearth is raised less than 4 inches
• 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 5-inch fresh-air intake register with airtight damper (SBI AC01349) — closable outside-air damper; do not close while the insert is in use
• 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 rigid fire screen (SBI AC01299) — not permitted for open-door use in the United States or in Canadian provinces/jurisdictions with particulate-emission limits; never leave the insert unattended when used with a fire screen
• 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

The 65,000 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 9,800–52,200 BTU/hr band per the CSA B415.1-10 stack-loss method. That's a notably wide range — the Osburn 1700-I delivers usable heat from very low burn rates suitable for shoulder-season heating, up through strong sustained output for cold-snap winter heating.

A realistic burn cycle from a packed load of well-seasoned hardwood produces a 30–45 minute warm-up, 2 hours of strong sustained heat once the firebox and surrounding masonry come up to temperature, then a gradual decline over the next 2–3 hours with a coal bed remaining. Total useful heat from one full pack is realistically 5–6 hours, occasionally approaching the 7-hour manufacturer maximum with dense hardwood, mild weather, and a packed coal bed.

The masonry around the insert acts as a thermal mass. Once the surrounding brick or stone is up to temperature, it continues radiating heat into the room well after the active fire has died down. This is one of the underappreciated benefits of an insert versus a freestanding stove — the masonry stores and releases heat on its own cycle. The first hour from a cold start is the slowest because that mass has to come up to temperature; once it's hot, response time is faster.

The 144 CFM heat-activated blower is what gets the heat into the room. Because most of the insert's firebox sits inside the masonry cavity, the radiant heat that would otherwise reach the room from a freestanding stove is partly absorbed by the surrounding brick. The convection jacket around the firebox captures that heat and the blower pushes it out into the room. The 144 CFM rating is notably stronger than the 90 CFM blowers used on smaller inserts in the line — more aggressive heat distribution and more effective at moving heat out of the masonry cavity.

Allow the insert to reach operating temperature (approximately one hour from a cold start) before turning the blower to high speed. Per the manual, turning the blower on too early during start-up pulls heat away from the firebox and slows the build-up to clean combustion.

Air-wash glass stays largely clear during proper hot burns at moderate-to-high air settings. At low burn rates with marginally seasoned wood, the glass will tar. This is universal to non-catalytic inserts, not specific to Osburn.

Power-failure operation: the insert continues to burn safely without electricity — only the blower stops. Heat distribution drops noticeably without the blower because the masonry cavity absorbs most of the firebox radiation. Plan accordingly if you're buying this insert specifically as a power-outage heat source.

Insert, not a freestanding stove. The Osburn 1700-I requires an existing masonry fireplace plus a full stainless-steel chimney liner — there's no other approved installation path. Buyers without a masonry fireplace should look at the Osburn 1700 freestanding stove (same firebox platform, no masonry requirement) instead.

Medium firebox platform. The Osburn 1700-I is the middle size in the Osburn insert line — bigger than the Osburn 950, smaller than the Osburn Matrix Insert and Osburn 3500 Insert. For buyers in the 1,200–1,600 sq ft range it's the right fit; outside that range, step up or down.

Same chassis as the Enerzone twin. The 1700-I and the Enerzone Solution 1.7-I share the same SBI medium-insert chassis. Same firebox, same blower, same baffle, same burn time, same 68% HHV efficiency, same 2.4 g/hr emissions, same warranty schedule. The differences are aesthetic and brand-tier: the Osburn adds the configurable cast-iron door overlay (Black or Brushed Nickel) on top of the faceplate/trim choices and is positioned in the premium Osburn tier. Choose the Osburn for the door-overlay configurability and the premium positioning; choose the Enerzone for the silver-grooved styling at the Enerzone price point.

Powerful blower, audible blower. The 144 CFM blower delivers strong heat distribution but is more audible than the 90 CFM blowers used on smaller inserts. The rheostat lets you dial speed down for quieter operation when the room is up to temperature; high speed is most useful during the active heat-output phase of the burn cycle.

7-hour maximum burn is medium-class, not long-burn. A 1.86 ft³ non-cat insert gives you meaningful primary-heat capability across 1,200–1,600 sq ft, with realistic 5–6 hour burn cycles. If you want true 8+ hour overnight burns, step up to the Osburn Matrix Insert or to a catalytic insert with a real low-output mode.

The 1,800 sq ft figure is aspirational. The most consistent owner regret across medium inserts is buying for the high end of the manufacturer's heating range. If you need to reliably heat more than ~1,500 sq ft as primary winter heat in a cold climate or older home, step up a firebox size.

The blower is essential, not optional. Unlike a freestanding stove where the blower meaningfully improves heat distribution, on an insert the blower is what gets the heat into the room at all. Most of the firebox sits inside the masonry cavity, which absorbs radiant heat. The insert will run safely without the blower (useful in a power outage), but day-to-day heat into the room depends on the blower being on and working.

Existing fireplace dimensions are non-negotiable. The masonry opening must meet the manual's minimum dimensions (21 1/2" H × 27 1/2" W × 12 7/8" D). The Large faceplate can cover a larger opening, but cannot compensate for an undersized one. Measure before purchase.

Configuration is a one-time decision. Door overlay color, faceplate size, and trim finish are all configured at order, not field-swappable. The combinations let the insert fit many room layouts and aesthetics, but choose the configuration that matches the fireplace you're installing into — measure the opening and confirm the look before ordering.

2.4 g/hr emissions is mid-pack. The Osburn 1700-I is within the EPA 2020 cordwood limit (2.5 g/hr) but not class-leading on emissions. Buyers specifically wanting lower emissions for an EPA non-attainment county should compare against cross-shops or larger fireboxes with lower published rates.

Wood quality is not negotiable. The most common "the insert doesn't heat" complaint comes from owners running marginally seasoned wood. Secondary combustion works best with dry, properly seasoned fuel, ideally around 15–20% moisture. A pin-type moisture meter is the single best accessory for this insert.

First burns. The first few fires cure the high-temperature paint and condition the internal components. Burn two or three small fires first, then build bigger, hotter fires until the paint smell is gone. The smell can be strong; ventilate the room well and avoid prolonged exposure during cure-in.

Lighting. Per the manual's EPA loading procedure, the recommended method is a bottom-up build: split a start-up fuel log into 6 pieces, criss-cross them at 45 degrees on the firebrick in three rows from smallest to biggest, criss-cross 12–15 kindling pieces on top in three rows, place newspaper on top, and light. Leave the door slightly ajar (about 1 minute to 1:30) until the kindling is fully engaged, then close and latch the door with the air control fully open.

Air control. Single-lever, located underneath the ash shelf. Pull the handle completely toward you to open (HIGH burn rate). Push completely to close (LOW burn rate). Full open at light-off; gradually closed only after the load is fully engaged and stable secondary flames are established. The manual specifies closing the primary air control by small increments (about 1/16 inch at a time) between 4 and 15 minutes after a reload — too fast and the fire smolders.

Reload cadence. 2–3 hours between reloads in active heating use; up to 6 hours for a final overnight pack with the air shut hard. Per the manual's loading procedure, rake remaining charcoal toward the front of the firebox before loading. Place three logs east-west on the coal bed leaving about 1–2 inches of air space between the rear firebrick and the first piece, then two more logs slightly angled on top. Open the air for a minute or two before opening the door, open the door slowly to avoid smoke rollout, load, close the door, and run the air open until the load is fully engaged before reducing gradually. Do not elevate the fire by using a grate.

Burn in cycles, not single-log feeds. Do not attempt to produce steady heat output by placing a single log on the fire at regular intervals. Always place at least three (preferably more) pieces on the fire at a time so the heat radiated from one piece helps ignite the pieces next to it. Each load should provide several hours of heating.

Ash management. Empty ash every 2–3 days during full-time heating. The best time to remove ash is in the morning after an overnight fire when the insert is relatively cool but there is still some chimney draft to draw ash dust into the insert rather than into the room. Always dispose of ash in a tightly covered metal container on a non-combustible surface, well away from combustible materials — ash retains hot embers for days. Never store ashes indoors, in a non-metallic container, or on a wooden deck.

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. Brown stains at the lower corners mean smoky combustion. Do not clean the glass when the insert is hot, and do not strike or slam the glass door shut.

Door and glass gaskets. Per the manual, 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. Test all the way around the door. The latch mechanism is adjustable — remove the split pin with pliers and turn the handle one counterclockwise turn to increase pressure. Plan on every 3–5 seasons in regular use.

Door alignment. Per the manual, the door hinges are adjustable. If the door drifts out of alignment over time, loosen the pressure screws on the upper and lower hinges with a 3/32" Allen key, turn the adjustable hinge rods with a flat screwdriver to bring the door back into square, then retighten the hinge pressure screws. Routine adjustment, not a warranty issue.

Annual chimney sweep. Per the manual, the chimney liner should be cleaned and inspected at least once each year. Inspect every two months during the heating season until you know your creosote-formation rate; monthly is safer for new burners. If buildup reaches 1/8 inch, sweep immediately. The baffle and secondary tubes can be removed for sweep access. Insert installations make sweeping more involved than freestanding stoves — many owners hire a CSIA-certified sweep rather than doing it themselves.

Wood seasoning. Hardwood needs 12–24 months split, stacked off the ground, top-covered, with sun and wind on the sides. Don't trust supplier "seasoned" claims — use a pin-type moisture meter, split a piece in half, measure the fresh face. Manual target: 15–20% moisture. Wood above 25% will smolder, soot the glass, line the chimney with creosote, and undercut every published efficiency and emissions number on this page.

Blower maintenance. Keep the blower intake and fins free of dust. Vacuum dust accumulation annually. Do not oil the blower unless the blower manual specifically calls for lubrication. Replacement blowers and related service parts are available through Osburn/SBI dealers and parts channels if needed years out.

What never to burn. Per the manual and EPA fuel rules: no coal, garbage, yard waste, materials containing rubber or plastic, waste petroleum products, paint or paint thinners, asphalt products, painted or pressure-treated wood, railroad ties, manure or animal remains, plywood, particle board, paper products, asbestos materials, construction or demolition debris, salt-water driftwood, or unseasoned wood. This does not prohibit normal fire starters made from paper, cardboard, sawdust, wax, or similar substances when used only to start a fire. Burning prohibited materials destroys the firebox, voids the warranty, and releases toxic compounds into your home and the chimney.

The Osburn limited lifetime warranty applies to the original retail purchaser only and is non-transferable. The warranty applies to normal residential use only. Proof of purchase (dated bill of sale), model name, and serial number are required for any warranty claim. Online registration is recommended at osburn-mfg.com but not required if a dated invoice is retained.

Coverage by component

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.

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.