Indoor Wood Boilers

Super E210

The Super E210 is a heavy-duty residential indoor wood boiler. It is capable of producing 170,000btu/hr and will heat up to 4,000 square feet. The SE210 achieved 87% efficiency during testing without the use of thermal storage. Our stainless steel boiler vessels come with the industry’s best warranty!

The SE210 is an indoor wood gasification boiler. It meets the newest EPA emission requirements; it is also certified to meet the UL2523 standard for indoor installations. You can use this indoor wood boiler with any heating application (water-based, steam, forced-air). The Wood Gun has been tried and true for over 40 years! We created the Super E210 to reduce the labor involved that is found in a typical wood stove…

The Super E210 qualifies for at least two tax credit programs.

  1. The Federal Tax Credit of up to $2,000.
  2. The Efficiency Maine Rebate of up to another $6,000.


The Wood Gun™ wood gasification boiler by Alternate Heating Systems is one of the most efficient wood-burning devices on the market today. This uncompromising multifuel system is ideal for any residential application where conventional log wood is used as fuel. The Super E210 is capable of heating homes up to 4,500 square feet, subject to building design and construction.

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The firebox of our indoor wood boiler accommodates wood sizes ranging from unsplit logs to full rounds up to 10″. Typically, you only need to load the large firebox 2-3 times daily. The Wood Gun™ will handle wood of relatively high moisture content, as high as 29% moisture, freeing you from curing a 12–18-month supply of wood. Unlike European-style wood gasifiers, the our indoor wood boiler excels on full rounds of firewood.


Weekly cleaning allows for optimal performance. The easy-access front bottom inspection door, along with included ash rake, makes cleaning fast and convenient.

A high-velocity draft fan moves air through the wood allowing for an easy cold startup. After the gasification process begins, this air movement produces intense flames and very high temperatures in the gasification tunnel. In turn, the air flows through the heat exchanger, cleaning it as it passes through.

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Liquid-fuel Back up

Our indoor wood boilers can be fitted with either fuel oil, natural gas, or LP gas backup (non-UL version only). The Riello fuel oil burner will allow you the option of automatic backup. This allows you to save money by burning a renewable fuel source and the convenience of burning oil. The oil backup system is rated over 84% efficient. With an efficiency rating that rivals top-of-the-line oil units, you cannot go wrong.

Industries Best Warranty

Wood Gun boilers use ¼” thick Type 304 stainless steel in the construction of the firebox, heat exchanger, and door frames. We use Type 304 stainless steel for its unsurpassed quality and longevity. Our stainless-steel boilers show no signs of deterioration, even after well over 35 years of service. This is why we gave our Wood Gun vessels a 20-year warranty, with the first 10 years being completely covered, labor and materials! We stand behind our products and trust our team who builds them!


The Wood Gun™ wood gasification boiler, when installed, maintained, and operated properly, produces no visible smoke and prevents creosote formation in the chimney.

Stack Temperature

Exhaust stack temperature is one indicator of transfer efficiency. During combustion, temperatures reach around 2000° Fahrenheit. Amazingly, our exhaust stack temperature ranges from about 260-300° Fahrenheit. This stack temperature is unheard of in the industry. The Alternate Heating Systems Wood Gun™ is truly the pinnacle of wood-fueled heating devices!

The Super E210 has a second heat exchanger! The exhaust exits the swirl chamber and travel inside the insulated cabinet to the back of the boiler. We use this space to bring the combustion air around the exhaust. The second heat exchanger further cools the exhaust and preheats the combustion air. This unique design makes the Super E210 the most efficient Wood Gun yet. We can achieve nearly 90% efficiency in this wood boiler.

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How it works

When we heat the wood to roughly 250-350F, the wood releases its gas. This process is called pyrolysis. The induction fan draws the wood gas through the bottom of the firebox and into our uniquely designed refractory. We combine these wood gases with oxygen which creates super-heated and clean combustion in the refractory. The super-heated gases pass through the interconnected refractory tunnels and into our uniquely designed swirl chamber. This is where the bulk of heat exchange takes place. Above the heat exchanger, the superheated refractory continues to gasify the wood remaining in the firebox. After combustion, we use the residual ash and a high-velocity airflow to scrub the heat exchanger preventing any build-up. This process leads to unparalleled consistency in heat exchange.

The Super E210 indoor wood boiler cycles on and off much like an oil or gas-fired boiler. During the off-cycle, there is no consumption of fuel because oxygen is not present in the combustion chamber. The large superheated refractory mass will re-ignite the fuel automatically when a drop in water temperature signals the need for heat. Automatic re-ignition can take place as long as 4 hours or more after the last firing cycle depending on boiler size.

During the off-cycle, wood gas inside the firebox condenses on the inner walls forming a solid that will eventually fall off. This combines with the remaining fuel, adding energy that, in many other boilers, goes up the chimney.

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  • Qualified for 22% Tax Credit
  • The BEST warranty in the industry
  • Meets all EPA requirements
  • 1/4″ Stainless Steel Construction
  • Very Fuel-Efficient
  • Minimal Maintenance
  • Versatile Applications
  • Water Storage NOT Required
  • Made in Pennsylvania

Call For Pricing (717) 987-0099

Assembled Specifications

Highest Delivered Efficiency (%)


max BTU/hr


BTU/hr (8hr burn time)


Typical Heating Capacity (square ft)


Standard Door Opening (in)


Firebox Capacity (cubic ft)


Firebox Length (in)


Water Capacity (gal)


Width (in)


Height (in)


Depth (in)


Flue Size (in)


Weight (without gas/oil backup) (lbs)


Supply and Return (in)


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

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.

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

This option comes FREE with the SE210. 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 running which would blow the remaining heat out through the flue.

Oil/Propane/Natural Gas Backup

The Wood Gun wood boiler can be fitted with a backup fuel option. This requires a dedicated firing tube that must be built in during manufacturing.

The Super E210 is capable of producing 130,000 BTU/hr when burning oil, propane, or natural gas.

Automatic/Manual Switching

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

Variable Speed Induction Fan

This option comes free with every SE210. This enables the boiler to change the BTU output based on real-time needs. This is accomplished by upgrading the 1-phase motor to a 3-phase motor and controlling the motor with a Variable Frequency Drive.

Alternate Heating

Warnock Hersey Certification

WH certification is available on all Coal Gun boilers for an additional charge. This certification assures that the boiler complies to UL 2523 Standards. Some insurance companies may require this certification and it is the responsibility of the homeowner to determine the need for a WH certification on any boiler purchased.

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. This certification is included with the addition of the

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 is 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.