WOC100 Multi-Fuel Boiler

Ten Year Warranty

The WOC100 is our largest Multi-Fuel boiler. With 400,000 BTU/hr, it can heat buildings ranging from 7,000 to 11,000 sqft. Our trademark cast iron grate and Dual Draft systems allow us to burn various types of solid fuels (hard coal and soft coal) in the same combustion chamber and customize the airflow to maximize burn efficiency with each kind of fuel. It can also be configured to operate without electricity!

An Automatic Switchover feature is an excellent addition to the WOC100. Switching to oil if the water temperature drops due to a lack of fire gives you the flexibility and freedom to know that your home will not go cold if you, for example, decide to go away for the weekend.

The WOC100 Multi-Fuel Boiler comes standard with

  • #2 Fuel Oil Burner with Manual Switch-Over
  • Legacy Grate System
  • Large 16” Loading Door
  • Automatic Dual Draft System – Forced Draft Blower and Natural Draft Damper
  • Firebrick Lined Firebox
  • Water Cooled Baffle (for increased efficiency)
  • Hydro Tested to 60PSI
  • Constructed of ¼” Steel Plate
  • Honeywell Circulator Control Aquastat
  • Temperature/Pressure Gauge
  • ASME Tested Pressure Relief Valve
  • Load Door Smoke Flap

Our WOC100 Multi-Fuel boilers’ cost of ownership is one of the lowest in the industry—$40.00 – $80.00 per year on average!

Traditionally, Multi-Fuel boilers have been sold as wood/coal combinations. However, due to EPA Phase 2 regulations, these units are no longer sold for continuous use with wood.

To view our Multi-Fuel boilers that do not have an oil burner option. click here WC100

For automatic feeding boilers, please explore our Wood Gun or Coal Gun product lines.

  • Large Firebox
  • Flexible Fuel Options
  • Oil/Propane/Natural Gas Backup
  • Waste Oil Backup
  • Easy Maintenance
  • Cost Effective
  • Fuel Efficient
  • Lifetime Durability
Call For Pricing(717) 987-0099
Assembled Specifications



BTU/hr Oil or Gas


Typical Heating Capacity (square ft)


Weight (lbs)


Flue Size (in)


Fuel Type

Wood*, Hard Coal, Soft Coal

Optional Backup Fuel

Fuel Oil, Propane, NG, Waste Oil

Standard Door Opening


Firebox Capacity (cubic ft)


Firebox Length (in)


Water Capacity (gal)


Width (in)


Height (in)


Height to Flue Opening (Center) (in)


Depth (in)


Coal Capacity (lbs)


Electric Requirements

110V, 60Hz, 15Amp

Propane/Natural Gas Backup

Fuel oil backup is standard for WOC models but propane or natural gas back up options are available for an additional cost.

Automatic/Manual Switching

For #2 fuel oil, the backup system can function in an automatic switch-over scenario, with fuel oil taking over when the boiler has exhausted its coal fuel. For other fuels, such as natural gas or propane, switch-over is manual only.

Alternate Heating

Domestic Coil

This Domestic Coil features a 100° F rise at 5 gallons per minute, 50° water inlet temperature and 65 PSI water pressure. It is threaded into a 4 IN NPT threaded fitting provided on the boiler for this purpose.

Insulation Jacket

Our base unit Multi-Fuel boilers have no insulation on the outside of the boiler, allowing maximum heat radiation in the boiler room. If you prefer to circulate more of this heat, an insulation jacket can be added to the boiler. This insulation jacket is comparable to that used on the Wood Gun or Coal Gun boilers

ASME Certification

The ASME Certification guarantees the steel grade and weld quality of the boiler water jacket. Each ASME Certified water jacket has been pressure tested to 60 PSI, and includes a 30 PSI release valve.

Low Water Cutoff

A Low Water Cutoff senses the water level in the boiler’s vessel and will shut the unit down if the water level drops to an unsafe level. Available with automatic reset or manual reset.