27297-1-1010
Page 9
GAS SUPPLY
All gas piping must be installed in compliance with local
codes and utility regulations. In the absence of local codes
the installation must comply with NFCG NFPA 54/ANSI
Z223.1.
Note:
Never use plastic pipe. Check to confirm whether your
local codes allow copper tubing or galvanized.
Where permittted, flexible gas connectors must be certified
to the following standards:
— ANS Z21.24 Appliance Connectors of Corrugated Metal
Tubing and Fittings
— ANS Z21.45 Assembled Flexible Appliance Connectors
of Other Than All-Metal Construction
The above connectors may be used if acceptable by the
uthority having jurisdiction. The state of Massachusetts
requires that a flexible appliance connector cannot exceed
three feet in length.
A drip leg should be installed in the vertical gas supply pipe
run to the unit.
Manual Shut-off Valve
Some local regulations require the installation of a
manual shut-off valve and ground joint union external to the
appliance. The shutoff should be accessible for service
and/or emergency use. Consult the local utility or gas
supplier for additional requirements regarding the
placement of the manual shut off valve. Compounds used
on threaded joints of gas piping shall be resistant to the
action of liquefied petroleum gases.
Leak Testing
WARNING - FIRE OR EXPLOSION HAZARD
Never test for leaks with an open flame. Check all
connections using a commercially available soap
solution. A fire or explosion may result causing
property damage, personal injury or loss of life.
Failure to follow the safety warnings exactly could
result in serious injury, death or property damage.
After gas piping to the heater is complete, all connections
must be tested for gas leaks. This includes pipe connec-
tions at the main gas valve, emergency shutoff valve and
flexible gas connectors (if applicable). The soap and water
solution can be applied on each joint or union using a small
paintbrush. If any bubbling is observed, the connection is
not sealed adequately and must be retightened. Repeat
the tightening and soap check process until the bubbling
ceases.
Important Note:
When pressure testing the gas supply lines at pressures
greater than ½ psig (14 in. w.c.), the gas supply pip-
ing system must be disconnected from the appliance
to prevent damage to the gas control valve. If the test
pressure is less than or equal to ½ psig (14 in. w.c.),
close the manual shut-off valve.
Pressure Testing of the Gas Supply System
1. To check the inlet pressure to the gas valve, a 1/8 inch
N.P.T. plugged tapping, accessible for test gauge
connection, must be placed immediately upstream of
the gas supply connection to the appliance.
2. The appliance and its individual shutoff valve must be
disconnected from the gas supply piping system during
any pressure testing of that system at test pressures in
excess of 1/2 psig.
3. The appliance must be isolated from the gas supply
piping system by closing its individual manual shutoff
valve during any pressure testing of the gas supply
piping system at test pressures equal to or less than
1/2 psig.
Recommended Gas Pipe Diameter
Pipe Length Schedule 40 Pipe
Inside Diameter
In Inches
Tubing, Type L
Outside Diameter
In Inches
Nat.
L.P.
Nat.
L.P.
0-10 feet
1/2
3/8
1/2
3/8
10-40 feet
1/2
1/2
5/8
1/2
40-100 feet
1/2
1/2
3/4
1/2
100-150 feet
3/4
1/2
7/8
3/4
