High-Efficiency Wood Burning With Catalytic Combustion; Two Ways To Add Fuel - Vermont Castings Defiant 1975 Installation And Operating Manual

Defiant 1975 Non-Catalytic / Catalytic Woodburning Stove
®
high-efficiency wood burning
with catalytic combustion
A Defiant leaves the factory with the combustor pack-
aged separately.
In the United States, it is against the law to operate this
wood heater in a manner inconsistent with operating
instructions in this manual. The components of the cata-
lytic combustion system in your Defiant work together to
produce optimum conditions for secondary combustion.
When the damper is closed, smoke travels through
the catalytic element, which causes ignition of smoke
at temperatures of 500°-600° F (260°-315°C), half the
temperature normally required for unaided secondary
combustion.
The catalytic element is a ceramic "honeycomb" coated
with the catalytic material. The element is located in the
secondary combustion chamber, molded from a special
high-temperature insulating refractory material. The
chamber provides the correct environment necessary
for secondary combustion of the fuel (smoke).
Closing the damper exposes the smoke to the combus-
tor. If the combustor is at least 600°F (315°C), it will
begin to burn the smoke.
Closing the stove damper may also reduce the draft, so
to avoid putting out the fire or deactivating the combus-
tor, close the damper only when a fire is well-estab-
lished and the chimney is thoroughly warmed. When
starting a fire, wait until the fire is well established and
there is an ember bed of at least 3-4 inches before clos-
ing the damper.
Never kindle a fire with colored paper or paper that
has colored ink or a glossy surface, and never burn
treated wood, garbage, solvents, or trash. All of these
may poison the catalyst and prevent it from operating
properly. Never burn cardboard or loose paper except
for kindling purposes. Never burn coal; doing so can
produce soot or large flakes of char or fly ash that can
coat the combustor and cause smoke to spill into the
room. Coal smoke also can poison the catalyst so that it
won't operate properly.
In general, the fire must be sufficiently well-established
to ensure that catalytic activity is initiated. When first
starting a fire, a medium- to high- firing rate must be
maintained until the stove, catalyst, and fuel are all
stabilized at the proper operating temperatures, and the
chimney is warmed.
Even though it is possible for the fire to get quite hot
within a few minutes after a fire is started, the combus-
tor may stop working or the fire may go out if the fire
dies down immediately as a result of the damper being
closed. Once the combustor starts working, heat gener-
ated by burning the smoke will keep it working.
22
To determine whether the combustor is operating, ob-
serve the amount of smoke leaving the chimney when
the damper is activated and when it is not. This proce-
dure is described on Page 34.
Avoid using a full load of very dry wood in the firebox.
This may result in continuous very high temperatures in
the secondary combustion area and damage the com-
bustor. Wood which has been split, and stored under
cover for more than 18 months may be considered very
dry. If you must burn extra-dry wood, mix it with green-
er wood for a longer fire and less stress on the combus-
tor. Also, do not use a full load of dry slab wood or scrap
wood. For long burns, use a mix of dry and moderately
dry wood.

Two ways to add Fuel

The Defiant's griddle lifts for convenient top-loading of
logs, and is the easiest way to add fuel. (Fig. 34)
Fig. 34 Top loading is the best way to add fuel during regular
use. Front loading is useful for kindling a fire.
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However, the front doors open as well for adding an Intrepid
loading
occasional log to a fire. If the stove is equipped with 8"
11/00
(203 mm) stove pipe, the front doors may be opened
(or even removed) and the optional Defiant spark
screen placed in the opening for open-fire viewing. The
Defiant is not approved for operation with the front
doors open if equipped with a 6" (152 mm) chimney
connector or chimney.
To open the front doors, insert the handle into the door
latch stub and turn it to the left and up. (Fig. 35)
Clockwise to
Open
Counter-
clockwise
to Close
Fig. 35 To open the front doors, turn the handle clockwise.
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