Osburn 3500 Wood Insert OB03510

Osburn 3500 Wood Burning Fireplace Insert OB03510

The Osburn 3500 Wood Insert is a high-end wood log insert designed for maximum heat output and efficiency. It's one of Osburn's most popular units, known for its combination of high-quality combustion properties and a strategically positioned blower that efficiently circulates heat throughout a room. This EPA-certified appliance boasts a 77 percent efficiency rating, ensuring a clean burn. The firebox is lined with refractory bricks for even heat distribution, and the stainless steel secondary air system enhances gas combustion while reducing harmful emissions. With a heating area ranging from 500 to 2,100 square feet, it also features an automatic glass "air wash" system to keep the glass door clean without any extra effort. The unit is constructed from heavy-duty carbon steel, ensuring a durable product, and its metallic black color seamlessly integrates into any room's decor.

The Osburn 3500 offers numerous customizable aesthetic options as well. You can select a steel door overlay in either black or brushed nickel to match your room's decor. Additionally, there are regular and large faceplate trim options available to create a cohesive look for your hearth. This versatility allows you to tailor the Osburn 3500 to your specific style preferences and home design.

Osburn 3500 Wood Insert Features

• Sturdy Build: Crafted with robust black metallic carbon steel construction, ensuring long-lasting durability.
• High Efficiency: This unit is EPA-certified with an impressive 77 percent efficiency rating and a low emissions rate of 1.54 g/h. It can burn for up to 6 to 8 hours in slow combustion mode, maximizing fuel efficiency.
• Clean Glass: Featuring a unique glass air-wash system with a vacuum design that promotes efficient combustion, preventing creosote build-up on the glass door.
• Impressive Heat Output: Capable of delivering 75,000 BTUs of heat, making it suitable for heating areas ranging from 500 to 2,100 square feet.
• Included Blower: The package includes a premium quality 144-CFM convection blower, enhancing heat distribution throughout your space.

Tax Credit Elegibility

The Osburn 3500 wood insert is eligible for a US Tax Credit, click the link below to learn more.

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Documents & Downloads

Installation & Operation Manual

Dimensions Sheet

Osburn Product Catalog

Appliance Performance

• Fuel type: Dry cordwood
• Recommended heating area-ft²: 1,000 - 2,700
• Overall firebox volume-ft³: 3.5
• EPA loading volume-ft³: 2.88
• Maximum burn time: 10 h
• Maximum heat output-dry cordwood: 110,000 BTU/h (32.2 kW)
• Overall heat output rate: 17,200 BTU/h (5.0 kW) to 57,800 BTU/h (16.9 kW)
• Average overall efficiency (dry cordwood): 71 % (HHV) - 76 % (LHV)
• Optimum overall efficiency: 77 %
• Optimum heat transfer efficiency: 75 %
• Average particulate emissions rate: 1.6 g/h
• Average CO: 73 g/h

General Specs

• Manufacturer: Osburn
• Mobile Home Approved: No
• Manufacturer Part Number: OB03510-Config
• Recommended Heating Area (sq. ft.): 1000 - 2,700
• Door Type: Single, glass with cast iron frame
• Glass Surface: 18.875-Inches X 11.75-Inches
• Glass Viewing Area (sq. in.): 222
• Glass Type: Ceramic
• Opening Width: 19-Inches
• Opening Height: 9.875-Inches
• Ash Drawer: No
• Blower Kit Available: Yes
• Burn Time: 8 - 10 hrs
• Max Output - EPA test wood: 49,500 BTU/h
• Overall Depth: 29-Inches
• Overall Width: 30.375-Inches
• Overall Height: 24.875-Inches
• Firebox Depth: 20.175-Inches
• Firebox Width: 22.875-Inches
• Firebox Height: 12.875-Inches
• Firebox Volume (sq. ft.): 3.5
• Baffle: High heat-resistant C-cast
• Combustion Technology: Non-Catalytic
• Log Length (maximum): 22-Inches
• Log Positioning: Over width
• Steel Thickness (Top): 3/8-Inches
• Combustible side wall to unit: 19-Inches
• Combustible shelf to unit (US): 27-Inches
• Combustible top mantle to unit: 27-Inches
• Combustible side mantle to unit: 9-Inches
• Minimum Fireplace Opening - Width: 31-Inches
• Minimum Floor Protection (Front of Unit): 16-Inches USA / 18-Inches CAN
• Minimum Fireplace Opening - Height: 26.25-Inches
• Minimum chimney height (feet): 15
• Type of Chimney (°F): ULC S635, CAN/ULC-S640, UL 1777
• Recommended Chimney Diameter: 6-Inches
• Optimum Efficiency (%): 77%
• Emissions: 1.32 g/h
• Tested or/and listed as per applicable standards by: Interlek
• Fuel Type: Wood
• Weight: 540 lbs
• Overall Width: 30.375-Inches
• Overall Height: 24.875-Inches
• Made in USA: No

All Osburn Products come with a limited lifetime warranty. If you find any defects in the parts or workmanship, Osburn will repair or replace the defective product. Please click the link below to learn more about the specific warranty conditions.

Click Here to View Full Warranty

We offer FREE shipping on all products within the continental USA (lower 48 u.s. states)

The delivery will be made to your curbside. Similar to most ground shipments, signature may not be required. Be aware of any possible issues with a drop off delivery if you are not home, or if the weather is an issue. You are responsible for unpacking your Osburn Product, disposing of packing material and placing/installing the product in your house.

We will send you an email with your order shipment tracking information, so you can check with the shipping carrier directly to track the progress of your delivery. There is a 30 day window to voice any missing or damaged items. Please call us at 1-(640) 500-4847 and we would be happy to assist you.

Hassle free 30 days return and refund if the product isn't as described. Please read our return and refund policy for more information. Give us a call at 1-(640) 500-4847 to gain more information about this product.