Outdoor Boilers (Coal or Wood Burning)

LEGACY SERIES: Coal or Wood Burning Outdoor Boilers


Mahoning Outdoor Furnaces provides quality products, with a commitment to service with fair and reasonable pricing. We’re experienced in the manufacturing of outdoor boilers and pay attention to the details important to delivering the final product to our valued customers.

Our wood & coal burning outdoor boilers offer many unique advantages:

Mahoning outdoor boilers easily adapt to a variety of different heating requirements, whether forced air or hot water.

6 model sizes to choose from: 200, 300, 400, 500, 600, and 750

Outdoor Boiler Applications:

  • Residential – Heating and domestic hot water are provided by the same outdoor boiler.
  • Multi-Unit Buildings – One outdoor boiler can safely and efficiently provide heat and hot water for multiple buildings, as well as the domestic hot water for those buildings.
  • Hot Water – Heat your pool, hot tub, or spa.
  • Barns – Plenty of warm water, air, and heat to maintain valuable livestock.
  • Green Houses – Constant supply of warm air and warm water to facilitate year-round growing.
  • Churches – Control utility costs on large, hard to heat structures.
  • Body Shops – Eliminates dust and reduces fire danger from paint fumes.



  • Eliminates the need and expense for separate chimney inside the house.
  • Burning wood, a renewable resource, is less expensive than other fuels.
  • Convenience of supplementing one alternative fuel type with another fuel.
  • One unit heats your home and domestic hot water.
  • One heater can actually be used to heat multiple buildings.
  • The heater hooks to any existing forced air system, hot water system, or in-floor system.

Durable & Desirable Design Features:

  • ¼” plate steel water tank and firebox.
  • 24 gauge stainless steel exterior.
  • Additional portals for zone heating, such as a separate out build which needs to be heated.
  • Furnace water level and water temperature gauges.
  • Shaker grates with exterior handles, making ash removal easy.
  • Large capacity ash pit and generously sized ash cleanout door.
  • Installs with any existing forced hot air, hot water, and in-floor system.
 Safety Features:
  • The heater is outside, so all dirt, dust, fuel, and fire are isolated outside the house.
  • All Mahoning heaters are non-pressurized.


  • Product has a 3-year warranty and 1-year warranty on all electrical components.
  • Shaker grates and door gaskets are excluded from warranty coverage.
  • Water tank and firebox are made from 1/4” plate steel.
  • Exterior and smoke stacks are made of stainless steel.
  • Heater comes with a 3-year warranty and 1-year warranty on electrical components. (We do not warranty grates or door rope gaskets.)
  • Electrical connections and circulation pump are enclosed in an insulated cabinet.
Additional Options:
  •  3’ smoke stack extensions
  • Hot tub or swimming pool water heating coils
  • Second domestic hot water coil
  • Additional portals for zone heating
  • Nurse tank for large, domestic hot water demands
  • Heat exchangers in sizes to fit your heating needs
  • Air handlers for easy floor or ceiling mount
  • Flat plate heat exchangers


Outdoor Boiler Models & Specifications:

Model (Standard) 200 300 400 500 600 750
Firebox Length 36" 48" 60" 60" 60" 72"
Firebox Opening 22" x 22" 22" x 22" 22" x 22" 22" x 22" 50" x 50" 50" x 50"

BTU Output (Per Hour)

Standard Firebox

150,000 225,000 300,000 375,000 700,000 900,000
Multi-Fuel Burner 75-150,000 75-225,000 75-300,000 75-375,000 N/A N/a
Dimensions 48"W x 56"D x 70"H 48"W x 68"D x 70"H 48"W x 82"D x 70"H 54"W x 82"D x 76"H 78"W x 96"D x 99"H 96"W x 96"D x 99"H


Standard Model

Multi-Fuel Model

2350 lbs.

2600 lbs.

2700 lbs.

3200 lbs.

3300 lbs.

3800 lbs.

4100 lbs.

5000 lbs.

11,000 lbs.


12,000 lbs.


Water Capacity 228 gal. 290 gal. 352 gal. 551 gal. 800 gal. 1100 gal.


Mahoning Outdoor Boilers are for outdoor use only.  

Mahoning Outdoor Furnaces’ heaters may be restricted in some states, due to state regulations, which vary by state. The Mahoning Skye Series V is an EPA Phase 2 Qualified product.