The new GS series continues the Heatmasterss tradition of rugged, easy to use outdoor wood furnaces. The GS is our basic model offering great features and a new low introductory price.

But, if you’re looking for a furnace that may be used indoors or out, and one that has even more features visit the G Series page.

Firebox
(W” x L” x H”)

19 x 20 x 30

Firebox Door
(W” x H”)

16 x 16

Water Capacity
(US Gallons)

90

Approximate BTUs

120,000

Dimensions
(W” x L” x H”)

37.5 x 57 x 77

8 hour burn rate

47,772 BTU/hr

Emissions

.07lb/mmBTU

8 hour efficiency
(Lower heating value)

81.50%

8 hour efficiency
(Higher heating value)

75.80%

Annual efficiency
(Higher heating value)

68%

CO

NA

This is our most popular size of furnace. The G200s is a workhorse capable of supplying heat to a home and small shop or one large building. As always, our furnaces can also heat domestic water, swimming pools, hot tubs, garages, and more. The GS series gives you basic features at a low introductory price but if your’e looking for more, visit the G series page for more information.

Firebox
(W” x L” x H”)

28 x 30 x 36

Firebox Door
(W” x H”)

20 x 20

Water Capacity
(US Gallons)

195

Approximate BTUs

232,000

Dimensions
(W” x L” x H”)

51.5 x 70 x 87.5

8 hour burn rate

111,315 BTU/hr

Emissions

.07lb/mmBTU

8 hour efficiency
(Lower heating value)

85.0%

8 hour efficiency
(Higher heating value)

79.0%

Annual efficiency
(Higher heating value)

75%

CO

NA

One of the largest furnaces available, the capacity of this unit makes it suitable for many large load applications. It’s capable of heating up to four applications at the same time, a home and large shop or a commercial sized shop. And because it’s a GS model it offers the basic features you need for a low introductory price.

Firebox
(W” x L” x H”)

30 x 42 x 40

Firebox Door
(W” x H”)

20 x 20

Water Capacity
(US Gallons)

260

Approximate BTUs

340,000

Dimensions
(W” x L” x H”)

51 x 82 x 90

8 hour burn rate

180,409 BTU/hr

Emissions

.23lb/mmBTU

8 hour efficiency
(Lower heating value)

80.50%

8 hour efficiency
(Higher heating value)

74.8%

Annual efficiency
(Higher heating value)

74.4%

CO

NA

Take a quick video tour of our GS Series furnaces.

Rugged and Easy to Use

Easy for You

  • Less wood cutting – These high efficiency furnaces use up to 50% less wood than conventional furnaces, saving you time cutting and loading wood and cleaning ash.
  • Easy access hinged rear door – The insulated rear door is built with a unique hinge design which allows for easy access to the rear of the furnace and quick and easy removal of the door if required without the use of tools or hardware.
  • Safe easy-to-use dual firebox door latch – Our carefully designed latch catches the door so it doesn’t swing completely open and expose you to excessive heat.
  • Water Level Gauge –  That’s easy to read so you never have to worry about the status of the water
  • High Efficiency Heat Exchange Tubes – Our vertical heat exchange tubes keep ash and creosote from blocking the tube are also easy to clean.

An Outdoor Wood Furnace that’s Built to Last

  • 409 Stainless Steel – Titanium enhanced and corrosion resistant, it is the only product that can provide the right blend of longevity, heat transfer and other critical traits that meet the HeatMasterSS standard of excellence.
  • Heatmasterss warranty – We back each furnace with our best-in-industry Lifetime Limited Warranty which is twice as long as the leading mild steel competitor. It confirms our confidence in our products.
  • Rounded firebox – The rounded design gives the firebox more strength with fewer welds.
  • Draft Induction Fan – Draws air through the furnace to keep the airways clean.
  • ISO 9001 Certified – HeatMasterSS furnaces are built to the very highest manufacturing standards, employing top notch design and engineering.
  • Heavy duty multi-layer insulation – We feature a foil-backed insulation that won’t trap moisture, gives you high R values and has no seams for heat to escape.
  • Combustion Chamber – Our high efficiency chamber has a horseshoe refractory design to help create the cleanest, hottest burn.

Wood Gasification

Wood gasification is the most efficient process available for wood burning. Wood gas is generated in a high temperature reaction (>700° F) between the wood and a limited amount of oxygen. The heat and lack of oxygen “bakes” the wood, causing the gases in the wood to be released.

The wood gas mixture that is created in the firebox then gets forced through the base of the fire along with any ash that would come with it and burned at temperatures around 2000° F in the gasification chamber. This creates a very hot, very clean burn which helps you get the most out of your fuel. After the gas is burned, the heat is transferred to the water jacket using the heat exchange tubes. Normal exit temperatures of the exhaust are 200 – 300 F.

The most notable indicator of effective gasification is the lack of smoke exiting the chimney.
The gasification process creates longer burn times and can reduce wood consumption as much as 50% compared to a standard wood furnace.

What does it mean for you?

  • Less wood cutting
  • Less ash removal
  • Fewer emissions
  • Fewer trips to the furnace

Bottom line – more heat for less

EPA Certified

We exceed government regulations by over 75%.