Newmac CL 86-96C Installation, Operating And Service Manual page 14

Coal is not as easy to burn as wood. It requires patience and a very specific and regular procedure of loading, shaking,
adjusting, etc. If you do not follow the correct procedure, the coal fire will go out. This can happen in a very short space of time
and once the process of extinction has started, it is almost impossible to reverse.
After a coal fire goes out, all the coal must be emptied from the furnace and the complete starting process must be repeated.
The coal burning learning process is often long and frustrating, but once the proper procedure is established and followed, coal
burning becomes a reasonably simple process, with the benefits of long burn times and evenness of output over the entire
length of burn.
STARTING UP A NEW FIRE
The flue draft must be .05" W.C. to allow combustion gases to flow freely out the chimney. Turn the solid fuel thermostat up to
a setting well above th4e room temperature to start the draft fan. Use paper and dry kindling to start the fire.
Add small compact pieces of hardwood when the kindling is burning hot. Keep the draft slide plate in the ash door fully open to
establish a hot fire. The ash door may be opened for start-up. However, close the ash door before opening the fire door to
prevent smoke from emitting out the fire door opening.
When a substantial bed of red coals is built up start adding coal, small amounts at a time. Continue adding small amounts of
coal until there is a solid bed of burning coal. Do not add too much at one time. Allow sufficient time between each small
loading (at least 10 to 15 minutes) so that each loading has time to thoroughly ignite before the next load is put in. For
maximum burning efficiency, always fill the furnace to the highest level possible. A deep bed of coal always will burn more
satisfactorily than a shallow bed.
Keep the draft fan running until you are sure the fire is continuing to burn hot, then turn the thermostat to the desired room
temperature setting. If the ash door has been opened, close it to prevent over firing, which can severely damage the furnace.
LOADING
Coal should be added to the fire at least every twelve hours. Coal never should be added unless there is a reasonably hot fire.
If the fire is burning hot and there is a deep bed of coals, full loads of coal can be added at any time. However, if there is not a
deep bed of coals, it is best to add small amounts of coal at first.
SHAKING
Shaking should only be done only with a hot fire.
Shaking should be done at least once a day, but not more than twice a day.
Best results from shaking will occur if short "chopping" strokes are used rather than long even strokes.
The amount of shaking is critical. Too little or too much can extinguish a fire due to blocked air flow. The proper amount
normally occurs when red coals first start to drop through onto the bed of ashes. Be sure that a small amount of ash is left
on the grates to protect them from the direct heat of the burning coal. Grates must be kept level or they will warp.
MAINTENANCE
Ashes never should be allowed to accumulate in the ash pit so they in any way impede the flow of combustion air to the fire.
Excess ash accumulation can cause the fire to go out, and also can cause severe damage to the grates because they cannot
cool from a flow of air beneath them. Ashes MUST be removed daily and put in a metal container with a lid.
Clinkers can occur in any coal furnace. They are pieces of fused ash that are hard. They can become large, and therefore
cannot be shaken through the grates in a coal furnace. When there is an appreciable accumulation, the fire will go out because
insufficient air is allowed to pass through the clinkers to the burning coal. Once clinkers have formed, they can be removed
only from above the grates. This usually means the fire must be allowed to die out before they can be removed.
Clinker formation can occur from a number of different causes or a combination of causes. Some of these are as follows:
Too hot a fire (too much draft)
Too shallow a bed of coals
Too deep a bed of coals
Excess shaking
Poking the fire from the top
Poor quality coal – excess ash content
Too little air (draft) after a long hot fire
SAFETY
Whenever a loading door is opened, it always should be cracked slightly before fully opening to allow oxygen to enter and
burn any combustible gases that are present. Failure to do this could result in sudden ignition of the unburned gases when the
door is opened.
A furnace never should be filled with excess coal so that the flue gas exit is in anyway blocked or impeded. Burning coal
generates carbon monoxide. If the flue gas exit is blocked, the carbon monoxide can be forced out of the furnace into the room
with possible fatal consequences. Never burn coal in any furnace that does not have an airtight, unified chimney system. The
furnace should be used only with chimney systems that provide a strong, reliable draft. With the exception of the start up
period, an ash pit door never should be left open.
Do not use an automatic stoker with this furnace.
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