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(wood only)


The LOGWOOD Add-On Boiler is a true Wood-burning boiler designed for operation in combination with existing Oil or Gas fired central hot water heating systems. By the simple installation of an Add-On Boiler to your present heating system you will enjoy the many benefits of dual-fuel heating without having to buy a complete multi-fuel boiler.

Because the LOGWOOD Add-on Boiler gives the option of substituting coal or firewood for costly oil or gas fuels, it makes dramatic reductions in fuel costs possible. And because it ends your absolute dependence on oil or gas, it provides added security against shortages of these increasingly expensive and scarce fuels.


  • Closed Pressurized system.
  • Burns 24" or 36" long wood up to 10" in diameter.
  • Large Firedoor, 15" x 11" for easy wood loading.
  • Separate ash pit door.
  • Heavy cast Iron grates.
  • Adjustable fire and pit doors sealed with renewable gaskets assuring airtight design for controlled fire draft.
  • Non-electric, automatic draft regulator safety controls water temperature without electricity.
  • ASME pressure relief valve for positive safety.
  • Fusible (melt out) plug located in the top of the fire chamber will extinguish the fire should the boiler ever lose its water supply.
  • Heavy, 1/4" steel plate construction.
  • 5-year "Limited Warranty"

Safety tested by an Independent Testing Laboratory to the following standards: UL-726, CSA B366.1, and ETLM 78-1.


Logwood is a registered trademark and is manufactured by:

Marathon Heater Company, Inc.
13 Town Barn Rd. • PO Box 58
Richford, NY 13835

Phone: (607) 657-8113 | Fax: (607) 657-8114

E-mail us at: