14
•
Install a 1/8" NPT pipe plug fitting, accessible for test
gage connection, immediately upstream of the gas
supply connection to the furnace.
•
Use two pipe wrenches when making 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.
•
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.
–
Use listed gas appliance connectors in accor-
dance with their instructions. Connectors must be
fully in the same room as the furnace
–
Protect connectors and semi-rigid tubing against
physical and thermal damage when installed. En-
sure 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.
``
Location of Manual Valve
(Installed Ahead of Ground
Joint Pipe Union)
Height Required
By Local Code
Ground Joint Pipe Union
To Be Installed Ahead Of
Gas Valve
Drip Leg
Reducing Coupling
1/2" x 1/8" with 1/8"
Pipe Plug To Measure
Line Gas Pressure
Figure 12
General Furnace Layout
Upflow Installations
When the gas piping enters through the right side of the
furnace
, the installer must supply the following fittings
(starting from the gas valve):
• 90 degree elbow.
• Close nipple.
• 90 degree elbow.
• Straight pipe to reach the exterior of the furnace
(Figures 12 & 13).
Figure 13
Gas Inlet Through Furnace Right Side
A ground joint union, drip leg, and manual shutoff valve
must also be supplied by the installer. In some cases, the
installer may also need to supply a transition piece from 1/2"
to another pipe size.
Figure 14
Gas Inlet Through Furnace Bottom Side
(Upflow)
When the gas piping enters through the left side of the
furnace, the installer must supply the following fittings
(starting from the gas valve):
•
Straight pipe to reach the exterior of the furnace (Fig-
ures 14 & 15).
