Features
Clean Traditional Cast Iron
Our GM40 wood stove is styled with clean lines and offered in traditional black cast iron. Built for the wood stove purist.
TruHybrid Reliability
Our Green Mountain stoves exceed EPA clean burning standards. You can be sure they will burn clean today and for many years to come.
Soapstone Firebox Lining
The GM40 is lined with soapstone blocks. Soapstone absorbs the heat of the fire to give you long-lasting comfortable heat.
SAVE 30%: THIS STOVE IS ELIGIBLE FOR THE WOOD STOVE TAX CREDIT >>

Efficiency
79%
HeatLife
16
Hours of heat
EPA Certified
1.07
g/hr
Specifications
BTU: Up to 40,000
Efficiency: 79%
EPA Certified: 1.07 g/hr
Finish: Matte Black
Firebox Capacity: 1.32 cu ft
Flue Exit Diameter: 6
Flue Exit Location: Top
HeatLife: 16 Hours of heat
Heats up to: 1,400 sq ft
Maximum Log Length: 16″
Model: 8640
Stove Type: Green Mountain Wood Stove
Weight: 350
Accessories
Blower with Rear Heat Shield: 96-57400
Outside Air Adapter: 96-53400
Clearances
- Side: 14″
- Rear: 16″
- Corner: 14″
Single-wall connector pipe, no rear heat shield
- Side: 14″
- Rear: 13 ¾”
- Corner: 7″
Single-wall connector pipe with included rear heat shield
- Side: 14″
- Rear: 9 ¾”
- Corner: 7″
Double-wall connector pipe with blower kit heat shield
TruHybrid™
Ultra Clean Combustion Systems
All of our wood stoves exceed 2020 EPA standards so you can be sure they burn clean today and for many years to come.
Our TruHybrid™ stoves burn cleanly and efficiently before and after you engage the catalyst. The system combines primary and secondary combustion with tertiary combustion using a catalyst to take care of any unburned smoke particles and gases.
Learn More About TruHybrid
Our Materials
Each HearthStone is handcrafted using a combination of precision-made components in cast iron, soapstone, steel, ceramic, and various other materials. Our commitment to quality and attention to detail ensures that your product will serve you faithfully for years to come.
Soapstone
Soapstone is a natural material that absorbs the high heat of a fire, then radiates a gentle heat into the room. Soapstone warms the objects in your home, not just the air, resulting in a comfortable, livable heat.
Learn more about heating with soapstone
Cast Iron
Using selected raw and recycled material, our iron parts are produced in our foundry in Spain. Our modern casting facility guarantees durable, reliable, high-quality cast iron parts.
TruHybrid™ Catalysts
The catalysts used in our TruHybrid™ system are made from coated stainless steel to ensure a long life, few maintenance concerns, and reliably clean combustion.