Goodman Amana AMH8 Service Instructions Manual page 28

PRODUCT DESIGN
Flexible liners should be hung straight or nearly straight.
If it is spiraled in the chimney and in good condition, it
should be rehung. To do this, break the top seal; pull up
and cut off the excess liner length, and refit the top
seal. Use caution when doing this, as the cut edges of
flexible liners may be sharp.
The surfaces of the liner must be physically sound. If
gaps or holes are present, the metal liner must be re-
moved and replaced (Fix 4).
Finally, confirm that the metal liner is the correct size
for the appliances to be installed. Use the GAMA tables
and rules.
If a metal liner is not present, a clay tile liner must be
present, or the chimney must be lined (Fix 4).
Use a flashlight and small mirror at the cleanout or vent
connector 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
approved fire clay tile
reline the chimney (Fix 4).
Next, measure the size of the liner. It may be possible
to do 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 relined (Fix 4).
Check 6 - Dilution Air.
If gas-fired appliances are to be vented into a clay tile
liner, a source of dilution air is required.
Dilution air cannot be obtained through:
• Induced draft appliances
• Natural draft appliances with vent dampers
Sufficient dilution air can ordinarily be obtained through
the 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
relined (Fix 4).
Check 7 - Complete the Installation.
If Checks 1 through 6 have been satisfactory, and the
liner is an acceptable size as determined 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
28
amendments, then the clay tile liner can probably be
used as a vent for the gas appliances. However, the
installer must keep in mind the following factors which
may render the tile liner unsuitable for use as a vent:
• Extremely cold weather
• Long vent connectors
• Masonry chimneys with no air gap between the
liner and the bricks. (In practice, this can be diffi-
cult to detect.)
• Exterior chimneys (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 assume interior chimneys.)
If, in the judgment of the local gas utility, installer,
and/or local codes; one or more of the above factors is
likely to present a problem, the chimney must be re-
lined (Fix 4).
Fix 1 - Liner Termination.
Any cap or roof assembly used with a liner must be ap-
proved by the liner manufacturer for such use. The liner
and cap/roof assembly must then terminate above the
roof in accordance with the manufacturer's instructions.
In some cases, a shorter extension above the roof may
be possible with a liner than would be required with a
masonry chimney.
For further information on relining, see Fix 4.
Fix 2 - Change Venting Arrangements
If the masonry chimney has more than one channel, it
may be possible to vent the gas appliances into one chan-
nel and vent the solid or liquid fuel appliance(s) into
another channel(s). Do not vent an 80% furnace inside of
a metal liner with other appliances vented outside the
liner.
Alternatively, the homeowner may agree to discontinue
use of the fireplace (solid fuel appliance). If so, the tile
liner must be cleaned to remove creosote buildup. The
fireplace opening must then be permanently sealed.
If oil-fired appliance(s) are being replaced by gas-fired
appliance(s), the tile liner must first be cleaned to re-
move the fuel oil residue.
If none of the above options are practical, the 80% fur-
nace may need to be vented vertically with B vent.
Under some conditions a 90%+ furnace could be installed
rather than an 80%. The 90% furnace can be vented hori-
zontally or vertically through PVC pipe.
Fix 3 - Rebuild the Crown.
If the chimney crown is damaged, a qualified mason must
repair it in accordance with nationally recognized build-
ing codes or standards. One such standard which may be
referenced is the Standard for Chimneys, Fireplaces,
Vents, and Solid Fuel Burning Appliances, ANSI/NFPA
211.