Clayton 1602G, Owner'S Manual, Page: 18 / 24

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BULLETIN RC454
A GUIDE TO BURNING COAL IN YOUR FURNACE
Furnaces that are capable of burning coal usually will burn both
Bituminous and Anthracite coal. Anthracite is perhaps the best
coal fuel because of its long even burn time, high heat output,
and cleanliness which make it a good choice for the home. How -
ever, keep in mind it is a much more difficult fuel to use, requires
more care and patience, is not so widely available, and is usually
much more expensive than Bituminous.
SIZE OF COAL
Most sizes of Bituminous Coal will work in a coal furnace; for
best results we recommend large “nut” coal to small “egg” coal
(1-3/4” diameter to 4” diameter). When burning Anthracite, use
“egg” or “broken” with sizes between 2-5/16” thru 4-3/8”. Note
that it is important to the long life of your stove to buy coal which
has been sized and cleaned. Cleaning insures removal of rocks
and other minerals. Never use coal smaller than 1” or larger than
5” in diameter. Small sized coal will smother the fire. Too large a
size of coal will not burn well.
STOVE OPERATION
All coal fires should be started with wood which will allow the
fire to get hot enough to ignite the coal. The best ignition fires
utilize dry pine or other resinous soft woods as kindling, with
hard wood (oak, hickory, ash) added to increase the heat prior to
addition of the coal.
Before starting the fire, open the stove pipe damper (if epuipped),
turn the thermostat to high, open the ash pit door and feed door,
place newspaper and finely split kindling on the grate, light the
paper, add larger hard wood after the kindling is burning bright -
ly. Caution: Never use gasoline, lantern fuel, kerosene, charcoal
lighter fluid, or other flammable liquids to start or freshen up a
fire in any heater. Place the larger pieces of wood on the fire so
that they are slightly separated and form a level for the addition
of coal. It will take 10 to 20 minutes before this wood is thor -
oughly ignited. Adding coal too soon will cut the air supply and
smother the fire.
BURNING BITUMINOUS
Once your kindling and wood fire has produced a bed of well
established coals, start adding coal in layers allowing each to ig-
nite before adding more. Bituminous has a high volatile content
and, as a result, should be fired with the “conical method” - with
the highest portion of your fire bed in the center of the firebox.
The first flames will be long and generally orange or yellow and
produce quite a bit of smoke. As the gases burn off the flames
become shorter, change color and produce less smoke.
Once the fire is WELL ESTABLISHED add coal to the center of
the firebox forming the cone. Burning in this fashion allows heat
to drive off the volatile gases, and turbulence created increases
the burn efficiency. There will have to be some experimenting
with the individual setup as no two chimney’s or installations are
going to be the same. Just remember to allow enough air to enter
the firebox and keep the stove pipe damper open so that volatiles
are properly burned. Before refueling, take the time to break up
the cone a little with a poker, especially if it has caked over or
formed a crust. But, be careful not to mix the coal as this increas -
es the chances of forming clinkers. When shaking the grate(s)
be gentle. Just a few short movements - a couple of “cranks” - is
better than a lot of agitation. The objective is to remove a small
amount of the ashes without disturbing the fire. Stop when you
see a glow in the ashes or the first red coals fall into the ash pan.
Excessive shaking wastes fuel and can expose the grate(s) to very
high temperatures which can cause warpage or burnout.
For overnight operation (long duration burn time) shake the fire
and add coal, retaining the center cone. Once the volatiles are
burned off, close the feed door and adjust the stove pipe damper,
if epuipped. Then adjust the thermostat to the desired heat level.
More MAINTENANCE will be needed with bituminous coal
than with anthracite coal as more soot will collect on heating
surfaces and in pipes, requiring more frequent cleaning.
ANTHRACITE
Add a thin layer of coal (preferably smaller chunks) to the wood
fire, being careful not to disturb it too much or cut off the draft.
Then, add a second heavier layer after the coal is ignited and
burning well. If necessary, add a third layer to bring the coal up
to the top of the front liner (not above!). Be sure to close the ash
door.
Before adding further fuel, be sure to leave a red spot of glowing
coals in the center of the firebox to insure that the fire has not
been smothered and to help ignite the gases given off by the new
charge. A deep charge will give a more even heat and a longer
fire, but it may take one to two hours before the whole bed is
fully ignited.
When the fire is well established and the room is becoming
warm, partially close the dampers. Some experimenting will
have to take place with each particular setting of all dampers and
controls as the chimney provides the draft necessary to not only
exhaust the smoke, but to pull combustion air into the heater as
well - and no two chimney’s perform the same. Under ideal draft
conditions, one should be able to turn the secondary air supply
below the feed door (some models) to a near closed position -
but leave the ash pit damper at least partially open to prevent the
fire from going out. Adjust the stove pipe damper to reduce the
draft on the fire. With anthracite there will be short blue flames
above the coal, except when the fire is started or a new charge is
added. If, however, there is no flame then the fire needs more air
from the bottom (unless it is near the end of its burn cycle and
needs to be recharged).
Only when the coal is burned down to half its original depth it
is time to add fresh coal. When doing so, open the stove pipe
damper and turn the thermostat damper to high, which will al-
low the fire to burn off any accumulated gases. Open the feed
door, and with a small rake, hoe, or hooked poker pull the glow -
ing coals to the front of the firebox. Try not to disturb the fire too
much. Next, add a fresh charge to the back being careful not to
seal off the top. Close the feed door, but leave the spin damper
(or thermostat) open for a few minutes until the volatile gases
have burned off. It is not necessary to shake down the ashes each
time you refuel the furnace. Experience will be your best teacher.