GDS8 Installation Manual
13
Proper Chimney
Termination?
(Check 1)
Chimney channel
free of solid and
liquid fuel
appliances?
(Check 2)
Change venting
arrangements
(Fix 2)
Crown in good
condition
(Check 3)
Rebuild crown
(Fix 3)
and/or Reline
(Fix 4)
Reline
(Fix 4)
Reline
(Fix 4)
Cleanout free of
debris?
(Check 4)
Liner in good
condition?
(Check 5)
Reline
(Fix 4)
Dilution air
available?
(Check 6)
Complete the
installation.
(Check 7)
CHECK 1 - PROPER 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 addition, the chimney must terminate at least 3 feet
above any forced air inlet located within 10 feet. The chimney
must extend at least five feet above the highest connected equip-
ment 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.
P
OSSIBILITY
OF
PROPERTY
DAMAGE
,
PERSONAL
INJURY
OR
DEATH
DAMAGING
CONDENSATION
CAN
OCCUR
INSIDE
MASONRY
CHIMNEYS
WHEN
A
SINGLE
FAN
-
ASSISTED
C
ATEGORY
I
APPLIANCE
(80% AFUE
FURNACE
)
IS
VENTED
WITHOUT
ADEQUATE
DILUTION
AIR
. D
O
NOT
CONNECT
AN
80%
FURNACE
TO
A
MASONRY
CHIMNEY
UNLESS
THE
FURNACE
IS
COMMON
VENTED
WITH
A
DRAFT
HOOD
EQUIPPED
APPLIANCE
OR
THE
CHIMNEY
IS
LINED
WITH
A
METAL
LINER
OR
T
YPE
B
METAL
VENT
. A
LL
INSTALLATIONS
USING
MASONRY
CHIMNEYS
MUST
BE
SIZED
IN
ACCORDANCE
WITH
THE
APPROPRIATE
VENTING
TABLES
. I
F
AN
80%
FURNACE
IS
COMMON
VENTED
WITH
A
DRAFT
HOOD
EQUIPPED
APPLIANCE
,
THE
POTENTIAL
FOR
CONDENSATION
DAMAGE
MAY
STILL
EXIST
WITH
EXTREMELY
COLD
CONDITIONS
,
LONG
VENT
CONNECTORS
,
EXTERIOR
CHIMNEYS
,
OR
ANY
COMBINATION
OF
THESE
CONDITIONS
.
T
HE
RISK
OF
CONDENSATION
DAMAGE
IS
BEST
AVOIDED
BY
USING
MASONRY
CHIMNEY
AS
A
PATHWAY
FOR
PROPERLY
SIZED
METAL
LINER
OR
T
YPE
B
METAL
VENT
.
WARNING
Wash
Clay Tile Size: 8" x 8" x12"
(Each x 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 Connector
Basement Floor
F.A.F. Vent
Connector
Typical Multiple Flue Clay Tile Chimney
CHECKLIST S UMMARY
This checklist serves as a summary of the items to be checked
before venting an 80+ furnace into a masonry chimney. In addi-
tion, we recommend that a qualified serviceman use this check-
list to perform a yearly inspection of the furnace venting sys-
tem.
This checklist is only a summary. For detailed information on
each of the procedures mentioned, see the paragraph refer-
enced 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 repre-
sents the best information on this subject which is currently
available.