Osburn 3500 EPA 2020 Wood Stove with Blower
Up to 10 hours on one load. The Osburn 3500 (OB03500) is an EPA 2020-certified non-catalytic wood stove with a 3.5 cubic foot firebox that holds up to 50 lb of cordwood, rated up to 110,000 BTU/hr on dry cordwood at 77% optimum efficiency and 1.6 g/h, for 1,000 to 2,700 square feet. It takes 22-inch logs behind a cast-iron-framed door with an 18-7/8" x 11-3/4" ceramic-glass view, stands on a pedestal with an ash drawer, vents through a 6-inch chimney, and ships with its 130 CFM variable-speed blower and heat sensor. It is approved for mobile-home and alcove installation. The door overlay completes it above and is priced on top; from $3,839 for the stove alone.
Choose the 3500 if wood is how you heat a large home through a hard winter: it is the biggest stove in the Osburn line, rated for 1,000 to 2,700 square feet, and one full load runs up to 10 hours. The blower and its heat sensor are already in the box, so the fan comes on by itself once the stove is hot, and the pedestal base carries the ash drawer. Finish the door in black or brushed nickel.
It is not right for a small room, a cottage or a tight modern space: the recommended range starts at 1,000 square feet and it is rated up to 110,000 BTU/hr. It is installed as a freestanding stove only, never in a factory-built fireplace, and in a mobile home it cannot go in a bedroom. In the United States it runs with the door closed; open-door burning with a firescreen is not permitted. It needs a 6-inch chimney that serves no other appliance, 14 inches from a combustible side wall and 36 inches clear in front, and a non-combustible floor protector on any combustible floor.
Specifications
With a single-wall connector the 3500 sits 14 inches from a combustible side wall, 13 inches from the back wall and 7-1/4 inches from the walls in a corner (USA); a listed double-wall connector brings the back to 6 inches and the corner to 7 inches, with the side unchanged. Leave 36 inches clear in front and at least 84 inches from the floor to the ceiling. On a combustible floor, the non-combustible floor protector runs 16 inches in front of the door opening and 8 inches beyond each side of it. The chimney is 6 inches — a UL 103 HT factory-built chimney or a lined masonry chimney — at least 12 feet from the top of the stove to the cap, with at least 15 feet of total height from the floor and 3 feet above the roof, reached through a 6-inch chimney connector. Lowered-ceiling, alcove and mobile-home layouts have their own clearance tables on pages 35 and 36 of the installation manual, and a certified heat shield or a wall shield can reduce clearances (see section 8.3 on page 38).
Features
- EPA 2020-certified non-catalytic firebox: 1.6 g/h emissions, 77% optimum efficiency, up to 110,000 BTU/hr on dry cordwood and up to 10 hours per load
- 130 CFM variable-speed blower and its heat sensor are in the box, so the blower starts and stops by itself with the stove's temperature
- 3.5 ft³ firebox holds up to 50 lb of cordwood, takes logs up to 22 inches (16-inch recommended, loaded east-west) and is rated for 1,000 to 2,700 ft²
- Cast-iron-framed door with 4 mm ceramic glass and an 18-7/8" x 11-3/4" view of the fire, on a pedestal base with an ash drawer
- Approved for mobile-home and alcove installation; 14" to a side wall and 13" to the back wall with single-wall pipe, 6" at the back with double-wall
Answers to common questions
What chimney does the Osburn 3500 need, and is any of it included?
None of the venting is in the box. The 3500 has a 6-inch flue collar and vents into a 6-inch factory-built chimney for solid fuel listed to UL 103 HT (2100 °F), or into a code-approved masonry chimney with a clay or listed stainless liner — an oversized masonry flue gets a listed 6-inch stainless liner. Plan at least 12 feet from the top of the stove to the cap and at least 15 feet of total height from the floor, 3 feet above the roof and 2 feet above anything within 10 feet; the chimney serves no other appliance. Between the stove and the chimney goes a 6-inch chimney connector: black single-wall pipe at least 24 gauge thick with no more than 10 feet of horizontal run and two 90° elbows, or a listed double-wall connector, which also cuts the clearances. The full venting rules are in section 9, starting on page 41 of the installation manual.
How close can it sit to a wall or in a corner?
In the USA, with a single-wall connector: 14 inches from a combustible side wall, 13 inches from the back wall and 7-1/4 inches from each wall in a corner. With a listed double-wall connector: 14 inches at the side, 6 inches at the back and 7 inches in a corner. Keep 36 inches clear in front and at least 84 inches from the floor to the ceiling. Lowered-ceiling, alcove and mobile-home layouts each have their own clearance table on pages 35 and 36 of the installation manual, and a certified heat shield or a properly built wall shield can reduce the clearances (section 8.3, page 38). Send us your room layout if you want it checked — we're here to help!
What goes on the floor under the stove?
On a combustible floor the stove needs a continuous non-combustible floor protector — sheet steel at least 0.015 inch thick, or ceramic tiles sealed with grout over a continuous non-combustible sheet — reaching 16 inches in front of the door opening and 8 inches beyond each side of it in the USA (18 inches in front and 8 inches at the sides and back in Canada), plus under any horizontal run of chimney connector with 2 inches to spare on each side. On a non-combustible floor such as concrete, no protector is needed.
What’s included, what’s required, and what’s optional?
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Included in the box: The stove body with its cast-iron-framed door and 4 mm ceramic glass, firebrick lining, C-Cast baffle and four stainless secondary air tubes; Pedestal base with ash drawer; 130 CFM variable-speed blower with HI-LO-OFF rheostat and heat sensor, packed in the firebox and screwed onto the back of the stove at installation; EPA 2020 certification, UL 1482 / UL 737 / ULC S627 listing and the Osburn limited lifetime warranty.
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Required to complete the installation, purchased separately: Door Overlay - the black or brushed nickel frame that finishes the front of the door; it goes on before the stove is first used; Venting - a 6" listed factory-built chimney (UL 103 HT) or a lined masonry chimney, with a 6" chimney connector (see pg 41 in the installation manual); Floor Protection - on a combustible floor, a non-combustible protector 16 inches in front of the door opening and 8 inches beyond each side of it (USA), steel or grouted ceramic tile; Electrical - a 115 V outlet within reach of the blower's 8-foot cord, run so the cord never touches the stove or passes beneath it.
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Optional: The fresh-air intake kit for the pedestal (required in a mobile home, where the stove also needs an insulated fresh-air pipe — the flex pipe or a rigid insulated pipe), the insulated flex pipe itself, the fresh-air intake register with airtight damper, a glass ash lip, and a rigid firescreen for open-door burning where it is permitted (not in the United States) — the stove burns wood fully without any of them.
Is the blower included, and does the stove need electricity?
Yes, the 130 CFM variable-speed blower and its heat sensor are included; both screw onto the back of the stove. The blower plugs into a standard 115 V outlet on an 8-foot cord — keep the cord off the stove and never run it underneath. Set the HI-LO knob once the stove has been burning about an hour; with the heat sensor in place the blower then starts and stops by itself with the stove's temperature. The stove itself burns wood without power; only the blower needs it.
Can it go in a mobile home or an alcove?
Yes to both. In a mobile or manufactured home it needs Osburn's fresh-air intake kit for the pedestal with an insulated intake pipe, a double-wall connector only, a 6-inch double-wall factory-built chimney with at least 12 feet of flue from the top of the stove, and the base screwed to the floor; it never goes in a sleeping room. An alcove installation uses a double-wall connector and the alcove clearance table on page 35 of the installation manual.
How long does it burn, and what size wood does it take?
Up to 10 hours on a full load of dry cordwood, in Osburn's rating, and the 3.5 ft³ firebox holds up to 50 lb of it. It takes logs up to 22 inches, and 16-inch pieces loaded east-west — the long sides facing the glass — are what it is designed and EPA-tested for. Burn only seasoned wood at 15 to 20% moisture, never on a grate, and only a few 100% compressed-sawdust logs at a time; the warranty is void on anything but cordwood.
Does buying from The Torch Guys affect my Osburn warranty?
No. The Torch Guys is an authorized Osburn dealer, and Osburn's limited lifetime warranty runs through your dealer — if you ever need to claim, we deal with Osburn on your behalf. The combustion-chamber welds and the cast-iron door frame are covered for life on parts with 5 years of labour; the ceramic glass for life on parts; the baffle, air tubes, pedestal and ash drawer 7 years; the blower and its controls 2 years. It applies to the original purchaser, lifetime parts are replaced once, installation must be by a qualified technician, and it is void if anything but cordwood is burned. Keep your invoice and the serial number from the plate on the back.
