11
IO-242
5/04
10. Reconnect the draft blower power leads, flue pipe, and
pressure switch tubing. Make sure that all wires and the
pressure switch tubing are at least one inch from the flue
pipe, or any other hot surfaces.
11. Restore power to the furnace.
Counterflow units
are shipped with the induced draft blower
discharging from the top of the furnace. (“Top” as viewed for a
counterflow installation.) Vent the furnace in accordance with
the National Fuel Gas Code NFPA 54/ANSI Z223.1 - latest edition.
In Canada, vent the furnace in accordance with the National
Standard of Canada, CAN/CSA B149.1 AND CAN/CSA B149.2 -
latest editions and amendments.
WARNING
N
EVER ALLOW THE PRODUCTS OF COMBUSTION, INCLUDING CARBON
MONOXIDE, TO ENTER THE RETURN DUCTWORK OR CIRCULATION AIR SUPPLY.
VII. EXTERIOR MASONRY CHIMNEYS -
CATEGORY I FURNACES ONLY
An exterior masonry chimney is defined as a “Masonry chimney
exposed to the outdoors on one or more sides below the roof
line.” The ability to use a clay lined masonry chimney depends
on a parameter not associated with interior chimneys. This variable
is the geographic location of the installation. Researchers have
discovered that the winter design temperatures have a direct
impact on the suitability of this type of venting. In most situations,
the existing masonry chimneys will require a properly sized metallic
liner.
WARNING
P
O SSIBIL IT Y O F PRO PER TY DA M A GE , P ERSO N AL INJ UR Y O R D EAT H
DA M A GIN G CO N DE NS AT ION CA N O CC UR IN SID E M ASO N RY C HIM N E YS W HEN A
SIN GL E F AN AS SIS TED
C
AT EG O R Y
I
AP PLIA NC E (80 %
A FU E
FU RNA CE ) IS
VENT ED WIT HO UT AD EQ U AT E D IL U TIO N AIR .
D
O N O T CO NN EC T A N 8 0%
FU RN AC E T O A MA SO NR Y C HIM NEY U NL ES S T H E F UR NA CE IS CO M M O N V EN TE D
W ITH A D RAFT HO OD EQ UIPPED A PPL IA NCE O R T HE CH IM N EY IS L IN E D W IT H A
M ETA L L INER O R
T
Y PE
B
M ET AL VE NT .
A
L L INS T AL LA T IO N S USING M A SO NRY
CH IM N EY S M US T B E S IZ ED IN A CC OR DA N CE W ITH TH E A PP RO PRIATE V ENT ING
TA BL ES.
I
F AN 80 % F UR N AC E IS C OM M O N V EN TE D W ITH A DRA FT HO OD
EQ UIP PED A PP L IA NC E, T HE PO TE N TIA L F O R C O ND EN SA T IO N D AM AG E M AY
ST ILL EXIST W ITH EXT RE M ELY CO L D CO ND ITIO NS, LO NG VE NT CO NN ECT O R S,
EXTER IO R C HIM NE YS , O R A NY CO M B INA T IO N O F T HE SE CO ND ITIO NS.
T
HE
RIS K OF CO ND ENS AT ION DAM A G E IS BE ST AVO ID ED BY US ING THE M AS ON RY
CH IM N EY A S A PA TH WA Y F O R PR O PERL Y S IZED M ET AL LIN ER O R
T
YPE
B
M ETA L VEN T .
Wash
Crown
Clay Tile Size: 8" x 8" x12"
(Each x 24" Length)
Clay Tile Size Generally
12" x 12" (24" Length)
1/2" to 1" Air Space
Second Floor
First Floor
Attic Floor
Roof Line
Throat
Damper
Breech
Clean Out
Fan Assisted
Forced Air
Furnace
Natural Draft
Water Heater
Water Heater
Vent C onnector
Basement Floor
F.A.F. Vent
Connector
Figure 8 - Typical Multiple Flue Clay Tile Chimney
C
HECKLIST
S
UMMARY
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.
Proper Chimney
Termination?
(Check 1)
Line, terminate with
listed vent cap
(Fix 1)
No
Yes
Chimney channel
free of solid and
liquid fuel
appliances?
(Check 2)
Change venting
arrangements
(Fix 2)
No
Yes
Crown in good
condition
(Check 3)
Rebuild crown
(Fix 3)
and/or Reline
(Fix 4)
Yes
No
Yes
No
No
Reline
(Fix 4)
Reline
(Fix 4)
Cleanout free of
debris?
(Check 4)
Liner in good
condition?
(Check 5)
Yes
Yes
No
Reline
(Fix 4)
Dilution air
available?
(Check 6)
Complete the
installation.
(Check 7)
C
HECK
1 - P
ROPER
CHIMNEY
TERMINATION
.
A masonry chimney used as a vent for gas fired equipment must
extend at least three feet above the highest point where it passes
through the roof. It must extend at least two feet higher than any
portion of a building within a horizontal distance of 10 feet. In
