HearthStone Green Mountain 40 TruHybrid Wood Stove
The HearthStone Green Mountain 40 packs soapstone character into a trim package. At 23 1/4 inches wide and about 30 inches tall, it has a small footprint that's easy to plan a hearth around, and it still carries the look HearthStone is known for.
Inside, the firebox is lined with soapstone blocks. HearthStone's TruHybrid catalytic system handles the combustion, and the GM40 is rated at 79% efficiency (HHV) with certified emissions of 1.07 g/hr. It takes logs up to 16 inches in a 1.32 cubic foot firebox, and an optional blower kit is available if you want to move more warm air into the room.
What Makes the Green Mountain 40 Different
- Soapstone-lined firebox. Soapstone blocks line the firebox, visible every time you open the door.
- TruHybrid catalytic combustion. HearthStone's catalytic system is behind the GM40's 79% (HHV) efficiency rating and its 1.07 g/hr emissions.
- A compact footprint. At 23 1/4 inches wide and 19 3/8 inches deep, it keeps a small footprint on the hearth.
This listing is the HearthStone Green Mountain 40 TruHybrid wood stove, model 8640, part number 8640-0010, in matte black.
Key Specifications
- Combustion: TruHybrid catalytic combustor
- Efficiency (HHV): 79%
- Particulate emissions: 1.07 g/hr
- EPA certification: 2020 particulate emissions standard
- Heat output range (tested, per manual): 14,000 to 24,000 Btu (output)
- Firebox capacity: 1.32 cu ft
- Maximum log length: 16 in
- Flue size: 6 in
- Dimensions (W x D x H): 23 1/4 in x 19 3/8 in x 30 3/8 in
- Weight: 350 lbs
- Blower: Optional, Blower Kit 96-57400 (with rear heat shield)
- HeatLife (HearthStone rating): 16 hours
Efficiency, output, and HeatLife are HearthStone's ratings. Your results will depend on your home's layout, insulation, chimney, the wood you burn, and Maine weather.
Ownership & Maintenance
The TruHybrid system uses a catalytic combustor. Like any catalytic stove, the combustor should be checked periodically and will eventually need replacing. HeatLife is HearthStone's own burn-time rating, so treat it as a guide rather than a promise. Buy from us and you get ongoing service for our customers.
Come see the Green Mountain 40 and our other wood stoves at our Auburn, Brunswick, and Yarmouth showrooms. We'll help you choose a model, then plan the chimney, clearances, hearth protection, and installation.