Goodman Amana AMH8 Service Instructions Manual page 32

PRODUCT DESIGN
9. Connect the furnace to the building piping by one
of the following methods:
– Rigid metallic pipe and fittings.
– Semi-rigid metallic tubing and metallic fittings.
Aluminum alloy tubing must not be used in exte-
rior locations. In order to seal the grommet cabi-
net penetration, rigid pipe must be used to reach
the outside of the cabinet. A semi-rigid connector
to the gas piping may be used from there.
10.Use listed gas appliance connectors in accordance
with their instructions. Connectors must be fully in
the same room as the furnace.
11. Protect connectors and semi-rigid tubing against
physical and thermal damage when installed. Ensure
aluminum-alloy tubing and connectors are coated to
protect against external corrosion when in contact
with masonry, plaster, or insulation, or subjected to
repeated wetting by liquids such as water (except
rain water), detergents, or sewage.
E
DGES OF SHEET METAL HOLES MAY BE SHARP.
WHEN REMOVING HOLE PLUGS.
DIRECT/STANDARD INLET PIPING
When gas piping enters directly to the gas valve through
the standard inlet hole (upflow through the right side
panel), the installer must supply straight pipe with a
ground joint union to reach the exterior of the furnace.
NOTE: The rigid pipe must be long enough to reach the
outside of the cabinet to seal the grommet cabinet pen-
etration on 90% furnaces. A semi-rigid connector to the
gas piping can be used outside the cabinet per local codes.
INDIRECT/ALTERNATE INLET PIPING
When gas piping enters indirectly to the gas valve through
the alternate gas inlet hole the installer must supply
the following fittings (starting from the gas valve) to
reach the outside of the cabinet (NOTE: On the 90% fur-
naces the installer must swap the alternate inlet hole
plug with the standard inlet grommet in order to seal
the cabinet):
• Coupling.
• 90 degree elbow.
• 2 inch close nipple.
• 90 degree elbow.
• Straight pipe, with a ground joint union, to reach
the exterior of the furnace. NOTE: A semi-rigid
connector to the gas piping can be used outside
the cabinet per local codes.
32
CAUTION
U
SE GLOVES A PRECAUTION
GAS PIPING CHECKS
Before placing unit in operation, leak test the unit and
gas connections.
T
O AVOID THE POSSIBLITY OF EXPLOSION OR FIRE, NEVER USE A MATCH
OR OPEN FLAME TO TEST FOR LEAKS.
Check for leaks using an approved chloride-free soap
and water solution, an electronic combustible gas de-
tector, or other approved testing methods.
NOTE: Never exceed specified pressures for testing.
Higher pressure may damage the gas valve and cause
subsequent overfiring, resulting in heat exchanger fail-
ure. Disconnect this unit and shutoff valve from the gas
supply piping system before pressure testing the supply
piping system with pressures in excess of 1/2 psig (3.48
kPa). Isolate this unit from the gas supply piping system
by closing its external manual gas shutoff valve before
pressure testing supply piping system with test pres-
sures equal to or less than 1/2 psig (3.48 kPa).
PROPANE GAS TANKS AND PIPING
P
ROPANE GAS IS HEAVIER THAN AIR AND ANY LEAKING GAS CAN SETTLE IN
ANY LOW AREAS OR CONFINED SPACES.
PERSONAL INJURY, OR DEATH DUE TO FIRE OR EXPLOSION CAUSED BY A
PROPANE GAS LEAK, INSTALL A GAS DETECTION WARNING DEVICE.
A gas detecting warning system is the only reliable way
to detect a propane gas leak. Iron oxide (rust) can re-
duce the level of odorant in propane gas. Do not rely on
your sense of smell. Contact a local propane gas sup-
plier about installing a gas detecting warning system. If
the presence of gas is suspected, follow the instruc-
tions on the following page.
All propane gas equipment must conform to the safety
standards of the National Board of Fire Underwriters,
NBFU Manual 58.
For satisfactory operation, propane gas pressure must
be 11 inch WC at the furnace manifold with all gas appli-
ances in operation. Maintaining proper gas pressure de-
pends on three main factors:
1. Vaporization rate, depending on temperature of the
liquid, and "wetted surface" area of the container
or containers.
2. Proper pressure regulation. (Two-stage regulation
is recommended for both cost and efficiency).
WARNING
WARNING
T
O PREVENT PROPERTY DAMAGE,