GCES80 Installation Manual
16
• Install a drip leg to trap dirt and moisture before it can
enter the gas valve. The drip leg must be a minimum
of three inches long.
• Install a 1/8” NPT pipe plug tting, 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 shuto valve, between the shuto 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 ttings.
– Semi-rigid metallic tubing and metallic ttings.
Aluminum alloy tubing must not be used in exterior
locations.
– Use listed gas appliance connectors in accordance
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.
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.
Drip Leg
Ground Joint Pipe Union
To Be Installed
Ahead of Gas Valve
OPTIONAL:
Reducing Coupling
1/2” x 1/8” with 1/8”
Pipe Plug to Measure
Line Gas Pressure
Height Required
By Local Code
Location of Manual Valve
(Installed Ahead of
Ground Joint Pipe Union)
General Furnace Layout
A ground joint union, drip leg, and manual shuto 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.
When the gas piping enters through the side of the furnace,
the installer must supply the following ttings starting from
the gas valve:
• Nipple
• Elbow
• Straight pipe to reach the exterior of the furnace.
• A ground joint union, drip leg, and manual shuto
valve
must also be supplied by the installer.
When the gas piping enters through the side of the furnace,
the installer must supply , the following ttings starting from
the gas valve:
• Nipple
• Elbow
• Straight pipe to reach the exterior of the furnace.
A ground joint union, drip leg and manual shuto valve must
also be supplied by the installer.
Before placing unit in operation, leak test the unit and gas
connections.
T
O
AVOID
THE
POSSIBILITY
OF
EXPLOSION
OR
FIRE
,
NEVER
USE
A
MATCH
OR
OPEN
FLAME
TO
TEST
FOR
LEAKS
.
WARNING
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 specied pressures for testing. Higher
pressure may damage the gas valve and cause subsequent
overring, resulting in heat exchanger failure.
Disconnect this unit and shuto 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).
This unit must be isolated from the gas supply system by
closing its manual shuto valve before pressure testing of
gas supply piping system with test pressures equal to or less
than 1/2 psig (3.48 kPa).