Service Hints; Chimney Maintenance - USSC 1537M Owner's Manual

SERVICE HINTS

Do not expect a furnace to draw. It is the
chimney that creates the draft. Smoke spillage
into the house or excessive build-up of water or
creosote in the chimney are warnings that the
chimney is not functioning properly. Correct the
problem before using furnace. Possible causes
are:
1. The connector pipe may be pushed into the
chimney too far, stopping the draft (Fig. 6)
2. Do not connect two furnaces or a stove and
furnace into the same chimney flue.
3. The chimney used for a furnace must not be
used to ventilate the cellar or basement. If
there is a cleanout opening at the base of
the chimney, it must be closed tightly.
A draft reading of .05 to .06 w.c. is suggested for proper burning of this unit when using
wood or bituminous coal as fuel. When using anthracite coal, this draft reading is a

CHIMNEY MAINTENANCE

When wood is burned slowly, it produces tar
and other organic vapors, which combine with
expelled moisture to form creosote.
creosote vapors condense in the relatively cool
chimney flue of a slow-burning fire. As a result,
creosote residue accumulates on the flue
lining. When ignited, this creosote makes an
extremely hot fire.
When coal is burned, the products of
combustion combine with moisture to form a
soot residue which accumulates on the flue
lining. When ignited, this soot makes an
extremely hot fire.
The chimney should be inspected at least twice
monthly during the heating season to
determine if a creosote or soot build up has
occurred.
minimum reading.
Creosote and Soot - Formation and Need for Removal
4. If the chimney is operating too cool, water
will condense in the chimney and run back
into the furnace. Creosote formation will be
rapid and may block the chimney. Operate
the furnace at a high enough fire to keep the
chimney warm, preventing this condensa-
tion.
If the fire burns well, but sometimes smokes
5.
or burns slowly, it may be caused by the
chimney top being lower than another part
of the house or a nearby tree. The wind
blowing over a house or a tree, falls on top
of the chimney like water over a dam,
beating down the smoke. The top of the
chimney should be at least 3 feet above the
roof and be at least 2 feet higher than any
point of the roof within 10 feet (Fig. 5).
6.
See page 28 for list of trouble shooting tips.
If creosote or soot has accumulated, it should
be removed to reduce the risk of a chimney fire.
The
Chimney fires burn very hot. If the chimney
catches fire, immediately call the fire
partment, then reduce the fire by closing the
inlet air control. Pour a large quantity of coarse
salt, baking soda or cool ashes on top of the fire
in the firebox.
A chimney fire may cause ignition of
wall studs or rafters which you thought
were a safe distance from the chimney.
If you have a chimney fire, have your
chimney inspected by a qualified per-
son before using again.
15
CAUTION
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