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Classic Titanium Series Outdoor Wood Furnace

Classic CL 4030 Titanium Series - Specifications

In the U.S., the Classic CL 4030 is for non-residential applications only.

Door - 20"W x 20"H

Firebox - 40"L x 30"H x 26"W

Heat Transfer Area - 52 sq ft

Weight - 1,140 lbs

Water Capacity - 140 gal.

Measurements and Foundation Dimensions - Illustration

Included with outdoor furnace - Water Test Kit, Chimney Restrictor and two 4-foot chimney sections

Recommended (not required) - Ground Rod Kit (p/n 6593)



Constructed of titanium-enhanced stainless steel, the firebox has superior corrosion resistance and excellent heat transfer performance. This allows loading the firebox for longer burn times (in some cases up to 48 hours or more*) and burning some wood that is less than perfectly seasoned.

Central Boiler recommends burning seasoned wood when possible because dry wood burns better and provides more energy for heating your home. You'll burn less wood, saving you more money and time. That is, after all, what you want your outdoor furnace to do. *Actual burn times vary based on wood types, moisture content, heat load and ambient temperature.

Features and Benefits

  • More heat from the wood - the RippleTop design maximizes the surface area of the firebox and the HeatLock Baffle traps the heat in the heat collection area.
  • Easy to load - the large, insulated steel door is ergonomically designed for easy opening and closing and insulated to lock in the heat.
  • Easy to operate - the automatic draft control opens and closes as needed to control the water temperature in the system.
  • Durable and long-lasting - steel siding and powder-coating paint provide unequaled fit and finish and withstand the elements of time.
  • Dual Fuel Ready option - All Classic models are available as a Dual Fuel Ready model (standard on the CL 7260 and Pallet Burner) that allows the furnace to be fitted with an optional fuel oil, natural gas, or propane burner.


  1. Vent Cap - design eliminates evaporation.
  2. High Capacity Water Jacket - is tested multiple times to ensure welding integrity.
  3. Ripple Top Design - for increased heat transfer area and lower maintenance.
  4. Large, Insulated Steel Door - ergonomically designed with a large door for easy loading. Door is insulated for maximum efficiency. Door parts are powder-coated for increased paint durability.
  5. Automatic Draft Control - thermostatically controls the system water temperature.
  6. Skid Base Framework - makes installation easy with or without cement foundation. Only the CL 7260 and Pallet Burner require a slab.
  7. Welded Steel Framework - heavy-gauge framework engineered for enhanced strength of side panels and roof.
  8. Insulated Chimney - the chimney is a Type HT listed, factory-built chimney for wood-burning appliances. Two 4-foot chimney sections are standard.
  9. Rear Exhaust Outlet - increases efficiency and eliminates leaks and corrosion that competitors experience from chimneys that exit through the roof. Designed for easy inspection. Reduces heat loss by over 50%.
  10. Water-Filled HeatLock Baffle - creates secondary combustion area and traps heat in the firebox. Will not warp or burn out with extreme heat.
  11. Urethane Foam Insulation - insulation is sprayed on and forms a 100% airtight seal around the water jacket.
  12. Rectangular Firebox - engineered with stay pins. Will not collapse like round designs can.
  13. Ash Pan - 3/8" thick, formed ash pan is durable and easy to clean.

*Fan Draft option available for all models.

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Color Options

Color selections are close representations but are limited by processing and viewing conditions.

charcoal furnace swatch
green furnace swatch
Forest Green
taupe furnace swatch