Review of the QuadraFire Mt. Vernon AE - Maybe the World's Best Pellet Stove

If you own Quadrafire Mt. Vernon AE pellet stove or insert congratulations, you own one of the most technologically advanced pellets stoves made in the world. In 1986, Quadrafire stunned the hearth industry by developing the cleanest, most efficient burning wood stove that had ever been tested by the EPA. In 1990, keeping with tradition, they introduced the world's first fully automatic pellet stove. Sixteen years later they did it again with the Mt. Vernon AE.

What sets this pellet stove apart? Here are just a few highlights of what’s going on behind the scenes that make this model such a winner.

Aesthetics

The first thing you’ll notice is how stunning the stove looks on the hearth. It’s proportionately perfect with just the right height, width, and depth. The rear panel that houses the mechanical cabinet cuts back at about a 23° angle, pretty much hiding any of the stuff that would visually give up its identity as something else other than a traditional wood stove. There’s also nothing visible under the stove that looks out of place. From the top to the beautifully shaped legs, this stove looks and feels like a true cast parlor stove, reminiscent of cast revival wood stoves made so popular by Vermont Castings in the later part of the 20th Century. Unlike most other stoves or inserts in its class, all of the “tell-tale” controls and lights that would visually give away a pellet stove as mechanical are hidden, making it a welcome addition to the living room.

In keeping with the cast iron parkour style on both the freestanding Mt. Vernon and the insert, what most consumer notice right away, is the viewing glass, beautifully concealed behind two arched doors with webbing that can open up and allow for an unobstructed view of the fire, reminiscent of many 19th Century cast iron wood stoves. Toss in the optional wood log kit and you’d be hard pressed to know that these units are burning pellets.

Lastly, concerning aesthetics, and what is usually the biggest concern with folks shopping around for pellet stoves…is the sound that pellet stoves and inserts make when they are running. Quadrafire has addressed this problem beautifully with the Mt. Vernon AE. From startup, to the unit running on high, this stove is quiet, maybe even the quietest stove made. About the only sound you’ll ever hear is the occasional pellet drop or the self-cleaning mechanism during shut down.

Technology

Just like all Quadrafire stoves before it, the Mt. Vernon AE is controlled by a wall thermostat, this is where we start to notice a few differences. The wall thermostat for the AE is a two-way communicating thermostat that allows users to do more than just set the room temperature. This thermostat is packed with features that allow users to adjust flame height and blower speeds, choose between 4 different fuel types, run the stove in a 7-day programmable mode, adjust trim controls for high altitude, and best of all, it’s the only Quadrafire pellet stove model that offers error reporting. There’s a lot going on behind the scenes and the AE monitors all of it. If there’s ever a problem, the thermostat can usually dial into the exact issue, allowing users and service people the ability to quickly get the stove up and running again.

The AE gets its power from a regular 110v outlet but has a built-in power supply / conditioner for all of the low voltage electronics that operate the stove. This step-down approach to power allows the AE to consume very little electricity and still perform like a champ. Perhaps the best feature built into the stove, which I find hardly anybody ever uses…but it’s there, is the ability for the AE to operate from a 12v power source, such as a marine battery or solar panel array. Built into the power supply is an inverter / relay (normally about a $700 item when bought separately) that can automatically switch the stove from 110v power to 12v power in the event of a power loss. Simply purchase the optional power supply cord and connect it to a 12v marine battery, plug the stove into a wall outlet, and your battery will stay charged via the stove’s internal trickle charger. If the power goes out, the stove will automatically flip over to the 12v side and continue to run as normal. Very nifty.

How the Stove Operates

A wall thermostat controls every function of the Mt Vernon AE and allows the stove to operate in two different modes. The In-room sensing mode allows the user to adjust the thermostat for the desired room temperature and the stove will do the rest. Users can set a 7-day program for operation or override any of the programmed set points simply by raising or lower the temperature. If desired, there is a manual mode too, with 5 heat levels to choose from. In manual mode, the stove will not shut off unless it runs out of fuel. Manual mode is also the mode in which users would utilize the backup battery because the stove cannot auto-ignite without 110v.

Startup - Soft Start Cycle (SS-Low / SS-Med)

Once the fire is lit: The appliance moves into the low soft-start cycle as it continues to build the fire:

> More fuel will be added

> As the fire builds, the appliance will change to medium soft-start mode

> The heating cycle begins

Heating Cycle ( Auto / Man - L, ML, M, MH, H)

There are two choices in the Automatic / Manual menu of how the appliance will operate:

• Automatic Mode • The wall control will turn the heat output level up or down depending on how far the room temperature is from the desired temperature
  
  
• The digital display will read AUTO: M, i.e. automatic-medium level
  
  
• As the room temperature approaches the desired temperature, the appliance will turn down to lower settings
  
  
• When the home reaches the set temperature, the appliance will go into the shutdown cycle

Cleaning the Stove

Cleaning the Mt. Vernon is about as easy as it gets. Inside the stove, there is one large baffle that covers the rear of the firebox. This is removed by placing a flat-head screwdriver into two keys on the top left and right of the firebox and rotating them down. Simply lift about 1/4 of an inch and move the baffle, exposing the 115 cast iron fingers of the heat exchanger. Brush the fingers down lightly and vacuum the ash, replace the baffle and restart the stove.

Issues I’ve Found Over the Years

Thermostat

An advanced  piece of technology for 2006, the wall thermostat for the AE could use some updating. The display is dated and is back-lit by a quartz LCD, the readout of the thermostat generally doesn’t outlive the stove itself and often needs to be replaced 10 years or so after installation. The buttons often become weak and unresponsive. Because the wall thermostat is the only control for the stove, without it working properly, the stove cannot be used.

Thermocouple Wires

There are two thermocouples in the AE. One is located on the back of the drop tube for the fuel feed (Drop Tube TC) and the other is located directly over the burn pot (Firepot TC). Thermocouples are basically two solid core wires, one of copper and the other steel, that are welded together at the tip. The problem with the thermocouple setup in the AE is how they connect to the circuit board. The wire core of the thermocouple is “stronger” than the connection pins they attach to. If the wires are never touched, it isn’t a problem…but can become an issue if anyone starts trying to remove components, especially on the insert because access is very limited in the back of the stove. If the thermocouple wire is moved at all, the wire will move all the way back to the connections at the circuit board and can literally break away from the circuit board. Additionally, all of the fuses for the stove, especially the igniter fuse, is located on the circuit board. If you ever have to get to the fuses there are 15 connections to remove from the circuit board and often the thermocouple wires are disturbed during this process.