GMI 70 Wood Fireplace Insert Brown Enamel

Green Mountain Insert 90

From: $5099* MSRP

Our large flush insert combines stylish cast iron with our signature soapstone lining.


Enameled cast iron

The flush cast iron front of the GMI 90 is available in matte black or our brown enamel finish.

Soapstone firebox

Burn up to 20 inch logs in the soapstone lined firebox. Soapstone retains the maximum heat from you fire and radiates steady warmth as your insert burns.

Simple operation

Our non-catalytic wood insert is easy to use. A single lever air control lets you burn hot and fast or low and slow to keep warm through the night.






EPA Certified



Blower: Included

BTU: Up to 80,000

Efficiency: 64% HHV

EPA Certified: 1.22

Finish: Brown Enamel, Matte Black

Firebox Capacity: 2.5 cu ft

Flue Exit Diameter: 6

Flue Exit Location: Top

HeatLife: 8

Heats up to: 2,200

Maximum Log Length: 20″

Model: 8460

Stove Type: Wood Fireplace Insert

Weight: 475


Steel Surround: 94-5960010

Surround Extension: 94-5960110

Outside Air Adapter Kit: 94-53500

Fire Screen Insert: 94-69110

Linear Hook-Up Collar: 94-67500

Mantel Shield: 94-79700

Offset Liner Adapter: 5700-007


To combustible mantel from bottom of insert: 40-3/4”

To side trim from side of insert body: 9-1/2”

To side wall from side of insert body: 19”

EPA 2020

A new low emission standard for solid fuel heaters takes effect in 2020.

On May 15th of 2020, new EPA regulations take effect which require wood burning heaters to emit less than 2 grams/hour of soot. This new rule has given HearthStone the opportunity to take a leadership position and develop some of the cleanest, most efficient stoves in existence today, thanks to our TruHybrid technology.

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 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.

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.

Precision Steel

High-quality steel components are formed using the most modern processes available to achieve the highest level of fit and finish.

& Options

Steel Surround: 94-5960010

Surround Extension: 94-5960110

Outside Air Adapter Kit: 94-53500

Fire Screen Insert: 94-69110

Linear Hook-Up Collar: 94-67500

Mantel Shield: 94-79700

Offset Liner Adapter: 5700-007

GMI 70 Wood Fireplace Insert Brown Enamel


Steel Surround, GMI-90


Steel surround, 3-piece assembly.

Surround Extension, GMI-90


The surround extension is installed between the cast iron faceplate and the steel surround, reducing the hearth depth required to install the fireplace insert.

Outside Air Adapter, GMI-90


Connect an outside air source directly to your fireplace insert. Recommended for air tight homes. 5 inch flexible pipe not included.

Fire Screen, GMI-90


The Fire Screen allows the user to burn the fireplace with the door open to enjoy the direct fire.

Mantel Shield


The mantel shield attaches to bottom of a combustible mantel to reduce clearances per NFPA 211 standards. Attach to the mantel with screws and ceramic spacers. 48 inches wide. It can be cut to fit specific installations.

Liner Hook-Up Starter Collar


The Liner Hook-Up Starter Collar connects to your chimney liner before you install the insert in the fireplace. It can then be easily and safely secured to the insert after the insert is placed in the fireplace, making the whole installation process easier.

Offset Liner Adapter


The offset adapter moves the connection point between the insert and the chimney liner up to 6 inches back.

Installation & Resources

GMi90 Owner’s Manual

Download the Green Mountain Insert 70 8450 Manual

Learn More

GMi90 8460 EPA Report

View the GMI-90 EPA Report

Learn More

Green Mountain Insert 90 8460 Spec Sheet


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