John Wood Commercial - AJWS - Manual (Page 13)

“National Fuel Gas Code” or “Natural Gas and Propane
Installation Code” for the recommended gas pipe size of
other materials. Follow the instructions below and reference
Figure 10 for gas piping installation.
1.
Install a readily accessible manual shut-off valve in the
gas supply line as recommended by the local utility.
Know the location of this valve and how to turn off the
gas to this unit.
2. Install a drip leg as shown. The drip leg must be no less
than 76mm (3 in) long for the accumulation of dirt,for-
eign material and water droplets.
3. Install a ground joint union between the water heater
and the manual shut-off valve. This is to allow easy
servicing.
4. Turn the gas supply on and check for leaks. Use a chlo-
ride-free soap and water solution (bubbles forming indi-
cate a leak) or other approved method.
Gas Pressure
Important: The gas supply pressure must not exceed the
maximum supply pressure as stated on the water heater’s
data plate. Minimum supply pressure should also be main-
tained per the data plate.
Gas Pressure Testing
Important: This water heater and its gas connection must
be leak tested before placing the appliance in operation.
• If the code requires the gas lines to be tested at a pres-
sure of 14 inches water column or greater, the water
heater and its manual shut-off valve must be discon-
nected from the gas supply piping system and the line
capped.
• If the gas lines are to be tested at a pressure less than
14 inches water column, the water heater must be iso-
lated from the gas supply piping system by closing its
manual shut-off valve.
U.L. recognized fuel gas and carbon monoxide (CO) detec-
tors are recommended in all applications and should be
installed using the manufacturer’s instructions and local
codes, rules, or regulations.
Note: Air may be present in the gas lines and could prevent
the burner from lighting on initial start-up. The gas lines
should be purged of air by a qualified service technician
after installation of the gas piping system.
13
Explosion Hazard
Have a qualified service technician make sure L.P.
gas pressure does not exceed 13 inches water col-
umn. Failure to do so can result in death, explosion,
or fire.
WARNING
Drip leg
Check with
local utility
for min. height
Ground
Joint
Union
Manual Gas
Shut-off Valve
Figure 10: Gas Piping