Service manual

CTH2-SERIES INSTALLATION, OPERATION AND SERVICE MANUAL
38
SECTION 9: GAS PIPING
Install the gas hose as shown in Figure 21. The gas
hose accommodates expansion of the heating
system and allows for easy installation and service of
the burner. Before connecting the burners to the
supply system, verify that all high pressure testing of
the gas piping has been completed.
There is an expansion of the tube with each firing
cycle. This will cause the burner to move with respect
to the gas line. This can cause a gas leak resulting in
an unsafe condition if the gas connection is not made
in strict accordance with Figure 21.
Meter and service must be large enough to handle all
the burners being installed plus any other connected
load. The gas line which feeds the system must be
large enough to supply the required gas with a maxi-
mum pressure drop of 1/2" w.c. When gas piping is
not included in the layout drawing, the local gas sup-
plier will usually help in planning the gas piping.
• Do not high pressure test the gas piping with
the burner connected. Failure to follow these
instructions can result in property damage.
• Check the pipe and tubing ends for leaks
before placing heating equipment into ser-
vice. When checking for gas leaks, use a soap
and water solution; never use an open flame.
FIGURE 21: Gas Connection with Flexible Gas Hose
WARNING
Fire Hazard
Tighten gas hose fittings to connect gas supply
according to Figure 20.
Gas hose can crack when twisted.
Gas hose moves during normal operation.
Failure to follow the
se instructions can result in death,
injury or property damage.
Flexible Gas Hose
Shut-Off Valve
(Included With Gas Hose)
12"
(30 cm)
Horizontal
45°
Rear View
Shut-Off Valve must be parallel to
burner gas inlet. The 2" (5 cm)
displacement shown is for the cold
condition. This displacement may
reduce when the system is fired.
2" (5 cm)
Side View
Description Part Number
1/2" Flexible Stainless Steel Gas Hose (US Models) 91412200
3/4" Flexible Stainless Steel Gas Hose (US Models) 91412203
1/2" Rubber Type 1 Gas Hose (Canadian Models) 91412206
3/4" Rubber Type 1 Gas Hose (Canadian Models) 91412207
Hold gas nipple securely
with pipe wrench when
attaching the gas hose.
Failure to follow these
instructions can result in
product damage.