10
Typical Multiple Flue Clay Tile Chimney
Checklist Summary
This checklist serves as a summary of the items to be checked
before venting an 80+ furnace into a masonry chimney. In
addition, we recommend that a qualified serviceman use this
checklist to perform a yearly inspection of the furnace venting
system.
This checklist is only a summary. For detailed information on
each of the procedures mentioned, see the paragraph referenced
with each item.
This inspection is based upon a draft topical report, “Masonry
Chimney Inspection and Relining,” issued by the Gas Research
Institute. While not yet finalized, we believe this report represents
the best information on this subject which is currently available.
Check 1—Proper Chimney Termination
A masonry chimney used as a vent for gas-fired equipment must
extend at least 3 ft (91.4 cm) above the highest point where it
passes through the roof. It must extend at least 2 ft (61 cm)
higher than any portion of a building within a horizontal distance
of 10 ft (3 m). In addition, the chimney must terminate at least 3 ft
(91.4 cm) above any forced air inlet located within 10 ft (3 m). The
chimney must extend at least 5 ft (1.5 m) above the highest
connected equipment draft hood outlet or flue collar.
If the chimney does not meet these termination requirements, but
all other requirements in the checklist can be met, it may be
possible for a mason to extend the chimney. If this will not be
practical, see “Fix 1—Liner Termination.”
A. Crown
B. Wash
C. Roof line
D. Clay tile size: 8" x 8" x
12" (24.3 cm x 24.3 cm
x 30.5 cm) (each x 24"
[61 cm] length)
E. Attic floor
F.
¹⁄₂
" to 1 " (1.3 cm to
2.5 cm) air space
G. Second floor
H. First floor
I. Water heater vent
connector
J. Natural draft water
heater
K. Basement floor
L. Fan-assisted
forced air furnace
M. Forced air furnace
vent connector
N. Clean out
O. Breech
P. Damper
Q. Throat
R. Clay tile size:
generally 12" x 12"
(30.5 cm x 30.5 cm)
(24" [61 cm] length)
A
B
R
C
D
E
F
G
H
I
J
M
K
L
N
O
P
Q
No
Yes
No
Yes
Proper chimney
termination?
(Check 1)
Line, terminate with
listed vent cap
(Fix 1)
Chimney channel
free of solid and
liquid fuel
appliances?
(Check 2)
Change venting
arrangements
(Fix 2)
No
No
No
No
Yes
Yes
Yes
Yes
Rebuild crown
(Fix 3)
and/or reline
(Fix 4)
Reline
(Fix 4)
Reline
(Fix 4)
Reline
(Fix 4)
Crown in good
condition?
(Check 3)
Cleanout free of
debris?
(Check 4)
Liner in good
condition?
(Check 5)
Dilution air
available?
(Check 6)
Complete the
installation.
(Check 7)
