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Merrimack Large Insert
30004671
4. Once a good ember bed of at least 3-4” (76 - 10 mm)
has formed, add the desired amount of wood and close
the primary air control to a medium-low setting. The fire
volume will diminish immediately, but the Merrimack
Large Insert will continue to heat up. Maintain control
of the fire using the primary air control, and remember:
reduce the setting for less heat, increase the setting
for more heat. Refer to the air control settings chart
on Page 10 for recommended settings at different burn
rates.
Do not over-fire this heater.
overfiring may cause a house fire, or can result in per-
manent damage to the stove. If an exterior part of the
Merrimack Large Insert glows, you are overfiring.
Reloading and Reviving a wood Fire
Set the air control on “High,” and wait at least fifteen sec-
onds for the draft to increase. Turn the convection blower
off. Open the doors slowly.
IMpoRTaNT: while the stove is hot, toss and sift the
coals with each stove loading. This loosens and helps
burn coals that become buried in the ash. push coals
away from the bottom air jet. creating this “void” helps
maintain a reliable fire.
Check the ash level, and remove excess ash. A primary
air hole located under the front brick provides air to the
coal bed. (Fig. 1) This hole should be cleared of ash for
proper performance.
ST1158
front bricks
Primary Air
Hole
Andiron
ST1158
Fig. 12
Keep primary air holes free of ash for proper perfor-
mance.
bed is less than -3” (51 - 76 mm), activate the automatic
setback feature. This will provide extra air to start the fire
flaming and ‘setback’ to the desired air setting once the
stove is heated.
Finally, adjust the air control and fan speed for your de-
sired heat level.
NoTe:
If the charcoal bed is relatively thick and your fuel
is well-seasoned, it is possible to add fresh fuel (smaller
pieces first), close the door, and reset the air control im-
mediately.
Special Tactics for cold-climate heating
The Merrimack Large Insert is capable of producing up to
55,000 Btu/hour and heating an area of up to ,000 sq. ft.
However, many factors affect heating performance and
can influence the extent to which the Merrimack Large
Insert can heat a given area.
A well-insulated home, located in a moderate climate and
with the Merrimack Large Insert located centrally in an
open floor plan, will be easier to heat than a drafty home in
the far north in which a Merrimack Large Insert is installed
on an exterior wall at the end of a long house.
In Fireplace Insert installations, over-sized chimneys can
produce less effective results than those that are properly
sized, and interior chimneys usually perform better than
those located outside the house.
Different results may be experienced even in the same
installation if you switch from burning good, dry wood to
wood that is partially rotted or inadequately seasoned.
To compensate for these factors in cold climates, it may
be necessary to operate the Merrimack Large Insert for
longer periods of time with the air control set to a higher
level more of the time.
Remove and Store ash Safely
Check the ash level before reloading the stove, remove
ashes if necessary. Turn off the fan before shoveling the
ash into your ash container.
Remove ash regularly, typically every one to three days.
The frequency will vary depending on how you operate your
Merrimack Large Insert; more wood is consumed at higher
heat output settings, and ash will accumulate faster.
Ash should be removed frequently and placed outdoors in a
metal container with a tight-fitting lid. The closed container
of ash should be placed on a non-combustible floor or on
the ground, well away from all combustible materials, pend-
ing final disposal. If the ash is disposed of by burial in soil
or otherwise locally dispersed, it should be retained in the
closed container until all cinders have thoroughly cooled.
Wood ash may be used as a garden fertilizer.
caUTIoN:
Never use your household or shop vacuum
cleaner to remove ash from the fireplace; always remove
and dispose of the ash properly.
Add the fuel, smaller pieces first. If it is necessary to use
wood smaller than the 18” (460 mm) optimum size, be
sure to fill the firebox as completely as possible by load-
ing the wood pieces alternately on the left and right. Split
wood will fill the firebox more completely and reduce the
frequency of reloading. If possible, stack wood diagonally
to maximize air spaces between fired pieces.
If you have an ember bed of at least -3” (51 - 76 mm),
the air setting may not need to be adjusted. If the ember
