GM9S80 Service Manual
SYSTEM OPERATION
18
d. Tile liner cracked
e. No tile liner
f. Salt staining at mortar joints. (White stains, and
mortar becomes sandy and/or erodes.)
It may be necessary to
A cleanout (dropleg) must be present such that the upper
edge of the cleanout cover is at least 12 inches below the
lower edge of the lowest chimney inlet opening.
A chimney without a cleanout could become partially blocked
by debris. If no cleanout is present, the chimney must be re-
found:
• Fuel oil residue
• Bricks
• Mortar or sand
• Pieces of the tile liner
• Rusted pieces of the metallic liner reline the chimney
If a metal liner is present, it must be checked. It cannot be
and in good condition.
the inside of the elbow or tee at the base of the liner. A small
amount of soot may be considered acceptable, provided
the installer vacuums it away. If rusted pieces of the liner
have collected here, the metal liner must be removed and
-
driver. If the screwdriver perforates the liner, or if the tapping
does not sound like metal hitting metal, the liner must be
Remember that all appliances must be vented inside the lin-
er. Venting one appliance inside the liner and another appli-
ance outside the liner is not acceptable.
vent must be supported so as to not come into direct contact
with the chimney walls or tile liner. If it is not, it can probably
be helpful here.
is spiraled in the chimney and in good condition, it should be
The surfaces of the liner must be physically sound. If gaps
or holes are present, the metal liner must be removed and
appliances to be installed. Use the GAMA tables and rules.
If a metal liner is not present, a clay tile liner must be pres-
-
nector to inspect the clay tile liner. If any of the following
problems are present:
• Tile sections misaligned
• Tile sections missing
• Gaps between tile sections
• Signs of condensate drainage at the cleanout or vent
connectors
• Mortar protruding from between tile sections
• Use of sewer pipe or drainage pipe rather than an
this from the cleanout. The liner must be at least as large
as the minimum size established by the tables in National
Fuel Gas Code NFPA 54/ANSI Z223.1 - latest edition and
in the National Standard of Canada, CAN/CGA B149.1 and
CAN/CGA B149.2 - latest editions and amendments. If the
liner is too small or too large, then the chimney must be
a source of dilution air is required.
Dilution air cannot be obtained through:
• Induced draft appliances
• Natural draft appliances with vent dampers
draft hood of a natural draft appliance only if the appliance’s
vent connector does not include a vent damper.
If dilution air will not be available, the chimney must be re-