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FIGURE 11 - CHIMNEY HEIGHT REQUIREMENTS
WHAT TO DO IF THE HEATER SMOKES OR BURNS POORLY OR EXCESSIVE CREOSOTE ACCUMULATES IN THE CHIMNEY
1. Open a window slightly to see if the conditions improve. If opening a window improved the performance of the heater or stops
the spillage of smoke into the room, the problem is caused by a slight vacuum in the room. The vacuum can be the result of the
room being so tightly constructed that the air removed from the room by the heater is not replaced by normal infiltration of air from
outside the room.
The vacuum can also be caused by the loss of air from the room through the kitchen or bathroom ventilating fans, other
chimneys or vents, etc. The only solution to this type problem is to reduce the air lost from the room or provide a source for air to
enter the room.
2. Check the pipes connecting the heater to the chimney for loose or unsealed joints that may allow air to leak into the
chimney system.
3. Examine your method of building and tending the fire in the heater. If you add too much fresh coal at each refueling, or
attempt to operate the heater at too low a combustion rate for the amount of coal present in the firebox, your failure to follow
proper practices may be causing the problem. Also check for ash buildup in the ash pan. Ashes can restrict air flow through the
burning coal.
4. Check the height of the chimney. A chimney that is too short will not develop sufficient draft or allow wind to interfere with the
draft. See figure 11 for correct chimney height.
5. Check the chimney for cracks or holes that might allow air to leak into the chimney. If the chimney is equipped with an ash
clean out, be sure the door is closed and fits tightly. The door may have to be temporarily sealed with tape or furnace cement to
be as air tight as required. An excellent way to check an exterior chimney for leaks is to preform a smoke test building a small
coal fire in the heater, adding a small amount of coal to the fire to make it smoke heavily, momentarily blocking the top of the
chimney, and watching for smoke to leak out of any opening or cracks.
6. Check the entire system for obstructions that could be causing resistance to the flow of smoke and gases up the chimney.
7. Check the size of the chimney flue liner. If the chimney flue liner’s inside dimension is smaller that 6 inches round or 8 inches
square, it will be too restrictive to the flow of smoke and gases. A chimney flue liner which has an inside cross-sectional area of
more that 85 square inches is too large, which will result in excess capacity, which means less draft and more creosote. If the
chimney flue liner is too large, it may be improved by restricting the top opening of the flue to a 6 inch round opening, or in more
extreme cases, the chimney may have to be relined with a smaller lining and a metal prefabricated chimney may have to be
replaced.
WHAT TO DO IF THE HEATER BURNS TOO RAPIDLY OR OVERHEATS
1. If the room in which the heater is located becomes uncomfortably warm on moderately cool days, it may be because
you are placing too much wood in the heater for the amount of heat required to heat your home. Although the
thermostatically controlled inlet air damper on the heater is intended to control the burning rate of the wood, a certain
amount of air must enter the heater at all times to assure the fire does not go out and the wood burns as cleanly as
possible. Thus you should adjust the amount of wood you put in the heater to the outdoor temperature. Placing
excessive wood in the heater will cause excessive creosote formation in the chimney, waste wood, and make the room
uncomfortably warm.
2. If the heater burns too rapidly or overheats, it may be because air is leaking around a loose door gasket or a fuel
feed door or ash door latching pawl and handle may need adjusting. Check thoroughly for leaks where air may be
entering the heater’s firebox.
3. If the heater burns too rapidly or overheats due to excessive draft as described earlier, you may wish to consider
purchasing a barometric damper top be installed in the heater’s chimney connector. The barometric damper should
be set to regulate a .06 draft through the heater. Check with your heater dealer.
