28
•
Always use a back-up wrench when making the
connection to the gas valve to keep it from turning.
The orientation of the gas valve on the manifold must
be maintained as shipped from the factory. Maximum
torque for the gas valve connection is 375 in-lbs;
excessive over-tightening may damage the gas valve.
•
Install a manual shutoff valve between the gas meter
and unit within six feet of the unit. If a union is installed,
the union must be downstream of the manual shutoff
valve, between the shutoff valve and the furnace.
•
Tighten all joints securely.
•
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 exterior
locations. In order to seal the grommet cabinet
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.
•
Use listed gas appliance connectors in accordance
with their instructions. Connectors must be fully in
the same room as the furnace.
•
Protect connectors and semirigid 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.
The gas piping may enter the left or right side of the furnace
cabinet. The installer must supply rigid pipe long enough to
reach the outside of the cabinet to seal the grommet cabinet
penetration. A semi-rigid connector to the gas piping can be
used outside the cabinet per local codes. 1/2” NPT pipe and
fittings are required. For models with an “L” shaped mani
-
fold, a 4 1/2” long nipple is required. For models with a hook
shaped manifold, a 2” long nipple is required.
A semi-rigid connector to the gas piping can be used outside
the cabinet per local codes. From the elbow, the length of pipe
and the fittings required will vary by the side chosen, location
of union and cabinet width. The union may be placed inside
or outside of the cabinet.\
Alternate
Gas Line
Location
Gas Valve
Burners
Manual Shut Off Valve
(upstream from
ground joint
pipe union)
Drip Leg
Grommet
in Standard
Gas Line
Hole
*Ground
Joint
Pipe
Union
*Ground
Joint
Pipe
Union
*NOTE: Union may be inside furnace cabinet where allowed by local codes.
Manifold
UPFLOW
Figure 39
Gas Connections
T
O
AVOID
THE
POSSIBILITY
OF
EXPLOSION
OR
FIRE
,
NEVER
USE
A
MATCH
OR
OPEN
FLAME
TO
TEST
FOR
LEAKS
.
WARNING
Gas Piping Checks
Before placing unit in operation, leak test the unit and gas
connections.
Check for leaks using an approved chloride-free soap and
water solution, an electronic combustible gas detector, 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 failure.
Disconnect this unit and shutoff valve from the gas supply
piping system before pressure testing the supply piping sys
-
tem 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 pressures equal to or less than
1/2 psig (3.48 kPA).
Propane Gas Tanks and Piping
I
F
THE
GAS
FURNACE
IS
INSTALLED
IN
A
BASEMENT
,
AN
EXCAVATED
AREA
OR
CONFINED
SPACE
,
IT
IS
STRONGLY
RECOMMENDED
TO
CONTACT
A
PROPANE
SUPPLIER
TO
INSTALL
A
GAS
DETECTING
WARNING
DEVICE
IN
CASE
OF
A
GAS
LEAK
.
S
INCE
PROPANE
GAS
IS
HEAVIER
THAN
AIR
,
ANY
LEAKING
GAS
CAN
SETTLE
IN
ANY
LOW
AREAS
OR
CONFINED
SPACES
.
P
ROPANE
GAS
ODORANT
MAY
FADE
,
MAKING
THE
GAS
UNDETECTABLE
EXCEPT
WITH
A
WARNING
DEVICE
.
•
•
WARNING
