151B0801 R5 3/28/2006
5
Fig. 2: Common Chimney Problems
Table 2: Common Chimney Problems
Refer to Figure 2
Key Trouble Diagnostic Remedy
A
Top of chimney
lower than
surrounding
objects
Observation
Extend chimney
above all
surrounding
objects within
30 feet.
B
Chimney Cap
or ventilator.
Observation Remove
C
Coping restricts
opening.
Observation
Make opening
as large as
inside of
chimney.
D
Obstruction in
chimney
Can be found
by light and
mirror reflecting
conditions in
chimney.
Use weight to
break and
dislodge.
E
Joist protruding
into chimney.
Lowering a light
on an extension
cord.
Must be
handled by
competent
masonry
contractor.
F
Break in
chimney lining.
Smoke test -
build smudge
fire blocking off
other opening,
watching for
smoke to
escape.
Must be
handled by
competent
masonry
contractor.
G
Collection of
soot at narrow
space in flue
opening.
Lower light on
extension cord.
Clean out with
weighted brush
or bag of loose
gravel on end
of line.
H Offset
Lower light on
extension cord.
Change to
straight or to
long offset.
I
Two or more
openings to the
same chimney.
Found by
inspection from
basement.
The least
important
opening must
be closed,
using some
other chimney
flue.
J
Loose-seated
pipe in flue
opening.
Smoke test.
Cementing all
pipe openings
should
eliminate leaks.
K
Smoke pipe
extends into
chimney.
Measurement
of pipe from
within or
observation of
pipe by means
of a lowered
light.
Length of pipe
must be
reduced to
allow end of
pipe to be flush
with inside of
tile.
L
Failure to
extend the
length of flue
partition to the
floor.
By inspection or
smoke test.
Extend partition
to floor level.
M
Loose-fitted
clean-out door.
Smoke test.
Close all leaks
with cement.
DRAFT REGULATOR CONTROL
This device is used in conjunction with conventional chimney
venting. This control (or draft regulator) automatically maintains
a constant negative pressure in the furnace to obtain maximum
efficiency. It ensures that proper pressures are not exceeded. If
the chimney does not develop sufficient draft, the draft control
cannot function properly. The draft regulator, must be installed
within the same room or enclosure as the furnace, and should
