Hearthstone Green Mountain 90 Wood Insert

Hearthstone Green Mountain 90 Wood Insert


Clean burning and efficient, with it’s flush cast iron faceplate and door the GMi90 is a beautiful choice from any home. the GMi90 can be order in either Matte Black or Brown Majolica Enamel finish. Durable cast iron and steel construction with a 1¼” soapstone lined firebox. The Soapstone lining offers lasting heat and a lifetime of trouble free service. Standard thermostat controlled fans turn on and off automatically with the heat of the fire and with a single lever air control the GMi90 is easy and efficient to operation. The GMi90 non-catalytic wood insert is easy to use. A single lever air control let’s you burn hot and fast or low and slow to keep warm through the night.

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.



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: 94-53600
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”



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.


Owners Manual

Spec Sheet