E1000 Wood Boiler

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The E1000 is the largest boiler in our wood gasification boiler line. It is available in carbon steel and stainless steel and can handle up to 50,000 square feet. Made in Pennsylvania since 1981, these incredible machines allow you to utilize the cheapest fuels, eliminate production wastes, and heat your building, greatly enhancing your bottom line.

The Wood Gun series of gasification boilers is one of the highest-efficiency-rated choices out there. While typical boilers waste two-thirds of wood’s energy potential, the Wood Gun catches and uses up to 2/3 more of the BTUs in wood, changing it all into clean, consistent heat.

The Wood Gun was designed to lessen the work involved in general maintenance…

The Wood Gun series can be utilized with any heating device (water-based, steam, forced-air).

The E1000 wood gasification boilers are typically ordered with an automatic feed option, which lets you use an assortment of wood particle fuels, ranging from wood dust and chips to shavings, pellets, and other wood wastes¹.

Additionally, with an AHS automatic feed system, only slight changes are needed if you want to put logwood in the firebox. The E1000 wood gasification boiler can accommodate wood sizes of up to 10 inches in diameter the Wood Gun and reduce a good amount of log-cutting jobs (the length of the firebox is shown below), with the potential to handle logs to a maximum of 40% moisture, it saves on wood drying time; and, due to our trademark Swirl Chamber’s Exhaust Scrubbing innovation, the Wood Gun’s heat exchanger can clean by itself—so the only maintenance you’ll have to do is ash removal on a weekly basis, and boiler cleaning only three times a season.

How the Self-Loading System Functions

Top Feed WG Big


Firebox Level Control

In a typical setting, particle fuel is stored in a large. Fuel is transported on request by an auger and a bin agitator, ensuring a uniform discharge of material. A fuel level sensor that utilizes a photoelectric sensor (3) supervises the height of the fuel in the fuel chamber (4) and turns on the auger instantly. When the fuel in the firebox gets to the level of the receiver, this beam is broken, and the sensor stops the feed system.

The AHS automatic feed system’s two main safety features are the rotary airlock (1) and the fuel valve (2). The fuel valve and rotary airlock separate the fuel being burned in the fuel chamber from the fuel in the loading system, preventing the fuel in the loading system from igniting.


Underneath the firebox is the combustion chamber, where we convert the smoke and creosote into usable energy. We make our gasification boiler’s combustion chamber of cast refractory sections arranged edge to edge to create three passages to lengthen the dwell time of the wood gas in order to achieve complete combustion. This material has properties and textures similar to firebrick. It helps to create the environment needed to achieve the high temperatures required to burn the smoke, creosote, and other wood gases. Slots in the refractory bricks provide passageways from the fuel chamber to the combustion chamber. Small fuel particles are prevented from falling through the slots by fuel diverter bricks (6). Fuel diverter bricks are raised and lowered based on the size and kind of fuel being used.

During the gasification process, the discharged gas flows under the fuel diverter and across the slots in the combustion chamber where more than  2000° F is achieved. The intense heat generated here radiates through the refractory lining (5). The wood in the lower portion of the firebox is heated, causing the water to evaporate out of the wood, which allows the wood to begin to gasify (pyrolysis).

Swirl Chamber

Our wood gasification boilers use a draft-inducing fan (8) in order to draw the gases into the combustion chamber. The fuel effectively burns upside down due to the negative pressure. This is important because it allows fuel to be loaded continuously without extinguishing the fire. Once the gases are drawn into the combustion chamber, they pass through the firetubes (9), where most of the heat exchange takes place. On a small-scaled Wood Gun like the one shown, only one firetube is present. Multiple firetubes are used to increase the surface area available for heat exchange in the larger models.

After the firetubes, the gases are given a swirling action as they pass through the swirl chamber (10) and into the cyclone ash separator (11). Here, ash is removed from the exhaust air and deposited for easy disposal. The exhaust passes through the Swirl Chamber in a swirling motion that scrubs the chamber, preventing much of the ash buildup that could decrease efficiency. Exhaust air then exits, which has cooled to about 350 F, through the top of the cyclone ash collector into the flue.

Water Temperature Control

During off-cycle, because all of the doors and the automatic air intake (air valve) are gasketed, we can eliminate any air from entering the boiler. This causes the fire to go out quickly and does not allow the boiler to make more heat than what is needed. Our huge superheated refractory mass immediately rekindles the fire and starts producing heat again when air is allowed back into the wood.

¹An assortment of gasses can be used, such as corn, nutshells, cherry seeds, and paper pellets. Fuel sources are restricted only by natural concerns, like the amount of soot produced, and fuel economy concerns, such as accessibility and BTUs per pound.

For residential boilers, see our Super E210.

  • Gasification
  • Range of Biofuels
  • Fuel-Efficient
  • Minimal Maintenance
  • Lifetime Durability
  • Versatile Applications
  • Automatic Feed Available
  • Standard ASME Certification
  • Made in the USA
Call For Pricing(717) 987-0099
Assembled Specifications



Typical Heating Capacity (square ft)


Weight (lbs)


Flue Size (in)


Fuel Type

Soft, Hard Logwood*, Biomass*

Optional Backup Fuel


Standard Door Opening (in)


Firebox Capacity (cubic ft)


Firebox Length (in)


Approximate Water Capacity (gal)


Width (cyclone removed) (in)


Height (in)


Depth (in)


Electric Requirements

220V, 60Hz, 20Amp

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.

Can be equipped with multiple coils as needed.

Smoke Exhaust Hood

The Smoke Exhaust Hood mounts over the loading door, capturing any smoke that may escape during the fuel-loading process. This smoke is then vented directly to the outside through a separate vent. When tolerance for smoke is low, the smoke exhaust hood is essential.

Low Temperature Shutdown

If all the fuel has been consumed in your boiler, the Low Temperature Shutdown Feature prevents the boiler from attempting to fire. This keeps the draft fan from blowing the remaining heat out through the flue.

Cycle Timer

This feature adds a timer that triggers the boiler to run for 10 minutes every 2 hours, even if there is no call for heat. This maintains an internal temperature above the kindling point, reducing the need to manually relight the unit during periods of low demand.

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.

Variable Speed Induction Fan

This enables the BTU output to be easily changed. This is accomplished by upgrading the 1-phase motor to a 3-phase motor and controlling the motor with a Variable Frequency Drive.

Automatic Feed

The Wood Gun™ series can be ordered with the ability to automatically feed itself wood particle fuels, such as sawdust, wood chips, shaving, pellets, etc. The Wood Gun™ auto-feed system loads the fuel into the firebox from the top. Only slight reconfiguration is required to still burn logwood in the firebox! This option comes with a photo-eye sensor, which controls when more fuel is needed, and an upgraded control center, which allows the user to easily control the entire system in one location. Touchscreen controls are available as well.

Additional Required Pieces:

  • Rotary Airlock – Rubber blades or machined stainless steel.
  • Fuel-Valve – acts as a second airlock, available in stainless steel.
  • Transition Tubes – available in stainless steel – connects the boiler to Airlock, Fuel-Valve, and Auger
  • Auger – available in nearly any diameter (4″, 6″, 8″, 10″) and any length
  • Diverter Bricks
  • Secondary Air Brick with cover

Low Pressure Steam

The Honeywell Aquastasts are switched out for Honeywell PressureTrolls and two Low Water Cutoffs are included. An automatic water fill valve and Steam Relief-Valve are also included. In some models, the vessel is changed slightly to allow for a larger steam shelf. The Wood Gun can produce steam up to 15 psi. To know what size steam boiler you need, first, figure the amount of BTU/hr needed for your home, then add 20% to the total. This extra 20% is only needed to create the initial head of steam.

Note: only available on Carbon Steel boilers.

Canister Pool Heater

Heat your pool with wood! Available in either Carbon Steel or Stainless Steel. This is a separate canister from the vessel.

Custom Engineering

At Alternate Heating Systems we have expert fabricators and engineers ready to tackle any design change! Whether it’s a custom bin, moving the cyclone to the other side, an extra load door, water storage tank, or whatever you may need to fit your application.