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Outdoor Coal Boilers

The Coal Gun outdoor boilers are ideal for people who are searching to save big on their time and their money! In typically three years, the efficient Coal Gun Outdoor will be able to start paying for itself.

Coal Guns have a completely automated feed and ash dumping system. They have a max hopper capacity of 3,500 pounds. That gives you the freedom of not loading the unit for up to 30 days! *subject to usage

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The Coal Gun uses Pennsylvania’s domestically mined anthracite coal and produces heat not only for a whole residence but for your domestic hot water as well. The best part is that is does all that for about 70% less cost than electric and nearly 50% less cost than traditional oil or gas systems.

The outdoor housing can be customized to complement the color of the user’s residence’s exterior wall or outbuilding. Call today for more information!

Each AHS Coal Gun is made from premium quality materials by skilled, devoted experts. Each unit is tested thoroughly before it leaves our factory to make sure it’s compliant with our premium standards of quality. In fact, we assure you that our product is devoid of defects in materials and workmanship*. Every Coal Gun comes fully equipped with all components required for operation and safety. Standard equipment includes an insulated boiler jacket, operating and high limit aquastats, totally enclosed motor and drive systems, pressure relief valve, and Thermo ash-monitoring control.

Our Coal Gun boilers are among the longest-lasting heating units in the market. Alternate Heating System’s dedication to high standards results in a long boiler life (some reported at 30 years and more) and years of trouble-free functioning.

The bottom line is that our high-quality standards will save you both time and money in your heating application.

How It Functions…

From the giant hopper, pea-sized anthracite coal is gravity fed into the coal pot. A draft fan pulls the air through the fire enhancing the combustion of the coal. The hot exhaust enters the heat exchanger, the Swirl Chamber. In the Swirl Chamber, the hot exhaust and fly ash are spun around in the chamber. This allows more heat released into the water and the swirling fly ash scrubs the walls allowing maximum efficiency all season. The cooled exhaust and the fly ash now enter the cyclone ash separator where the rest of the ash is deposited in the ash pan. Anthracite coal does not cause creosote or release any smoke!

The Consumption of Coal…

Several factors can affect the quantity of coal used such as your climate, and building construction. Because of its high efficiency, however, Coal Guns utilizes less coal than other units on the market and will greatly lessen your yearly heating costs.

Thermo Ash-Monitoring Control…

Every Coal Gun boiler uses our Thermo Ash-Monitoring Control which gives optimum utilization of your fuel. The Thermo Ash-Monitoring Control instantly regulates the temperature of the ash. From the temperature of the ashes, we know when to shake the ashes into the pan. This allows the Coal Gun to thoroughly burn every pound of coal.

The Thermo Ash-Monitoring Control very rarely needs adjusting to get more or less BTU/hr when moving from the mild season to dead of winter. The boiler automatically adjusts to the needed output throughout the entire burn season (a minimal on-site alteration may be required when the boiler is first installed). With the Thermo Ash-Monitoring controlled grate, it is likely for the fire to remain burning for days during periods of little to no use.

*Limited Warranty

Alternate Heating Systems boilers and furnaces are guaranteed against damages in materials and workmanship for the given times:

  • Boiler Vessel – 20 years
  • Grate S130/S260 -Lifetime
  • The length of guarantee will be between 30 days to 1 year for all other elements both  produced by Alternate Heating Systems and bought from vendors

A copy of the full guarantee text, detailing coverage, limitations, warranty claim procedure, and state law rights is available from Alternate Heating Systems.

Wood Siding

Our typical siding is corrugated tim, we provide the “barn siding” look as an option.

Domestic Coil

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

ASME Certification

The ASME Certification secures the steel quality and weld standard of the boiler water jacket. Each ASME Certified water jacket has been pressure tested to 60 PSI and comes with a 30 PSI relief 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 falls to a dangerous level.

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  • Smoke Free
  • Outdoor Use
  • Large Hopper
  • Minimal Maintenance
  • Cost Effective
  • 83% Efficient
  • Versatile Applications
  • Lifetime Durability

Call For Pricing (717) 987-0099

Assembled Specifications



Heating Capacity* (sqft)


Approximate Water Capacity (gal)


Width (in)


Height (in)


Length (in)


Approximate Weight (lbs)


Flue Size (in)


Return Tapping (NPT) (in)

(2) 1 1/2

Supply Tapping (NPT) (in)

1 1/2

Hopper Capacity

2,000 lbs

Alternate Heating

Wood Siding 

Our standard siding is ribbed sheet metal, we offer the “board and batten” look as an option.

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.

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 required for all commercial installations. The certification is also required for some residential installations depending upon local codes – it is up to the homeowner to determine the need for an ASME
certification on any boiler purchased.

Low Water Cutoff

Senses the water level in the vessel and shuts the unit down if the water level falls to an unsafe condition.