John Wood Atmospheric Vent Light-Duty - Manual (Page 5)

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III) GAS CONNECTIONS
Install the gas piping as shown in Figure 4. Use only new pipe and
fittings with clean-cut threads. Sealing compounds used on the
pipe threads shall be approved for use with natural and propane
gas.
Use gas piping of adequate sizing to ensure full gas input. Gas
piping material must be approved for use with natural gas and
propane fuels. All piping must comply with all local codes or , in the
absence of local codes, the latest edition of CAN/CGA B149.1
installation code in Canada / National Fuel Code ANSI Z223•1
(NFPA 54) in the USA. The final connection to the water heater is
made using 1/2” N.P.T.
Before connecting to the gas service, check that a properly sized
gas meter and regulator are available to service the water heater.
If other appliances are using the same meter and regulator,
ensure that the capacity of the meter and regulator matches that
of the combined input of all appliances connected to it.
• Ensure that the piping is large enough to satisfy the
requirements of all appliances connected to the gas service.
Undersize piping can restrict gas flow causing the water heater
to perform poorly. Improperly sized piping may pose a safety
hazard.
• A manual gas shut-off valve shall be installed in the gas line
near the water heater. A union is recommended for ease of
service.
• To trap dirt or foreign material in the gas supply, a dirt (drip) leg
shall be installed in the piping at the heater.
• Apply joint compound (pipe dope) to the male ends of the
threads before joining pipe sections. Use only compounds that
are compatible with natural gas and propane fuels. To prevent
damage to the gas valve, do not over-tighten.
Gas Pressure
GSW Water Heating Company recommends that the gas supply
pressure, as measured on the inlet side of the water heater
control, be set at 7.0“ water column for natural gas and 11.0“ water
column for propane gas. The above pressures must be measured
during water heater operation. The gas control supplied with this
water heater is designed for a maximum inlet pressure of 0.5 psi
(14” water column). For natural and propane gas do not exceed
0.5 psi (14” water column).
WARNING
Exposure to a higher gas supply pressure may cause damage to
the control, resulting in explosion or fire. Consult your local gas
supplier and gas authorities. DO NOT PUT INTO SERVICE IF
OVER-PRESSURIZATION HAS OCCURRED.
The minimum inlet gas pressure required is 4.5 “ water column
for natural gas and 11.0 “ water column for propane gas.
Purging Caution:
Gas line purging is required to eliminate air from the piping
system. Purging should be performed by persons experienced in
this type of gas service. Do not purge in confined areas or space
where ignition may occur. To avoid risk of fire or explosion ensure
the area is well-ventilated and all sources of ignition are de-
activated. Contact your local gas authority for local requirements.
IMPORTANT:
Disconnect the water heater from the gas piping
during any high pressure testing above 0.5 psi. Perform a leak test
at normal gas pressure on all fittings after all connections have
been made and the gas has been turned on. Soap test all
connections of the gas system - bubbles indicate leaks.
IV) WATER PIPE CONNECTIONS
Pipe and fittings should be installed in compliance with the
installation drawing. Have the installer show you where the water
shutoff valve is installed so that you know where and how to shut
the water off. It is recommended that such a valve be located in
close proximity to the cold water inlet of the water heater. Water
piping and fittings should be installed as shown in Figure 5.
NOTE: THE FITTINGS SUPPLIED WITH THIS WATER
HEATER ARE 3/4” NPT.
1. Close main water supply and drain the piping system where
water heater is to be connected.
2. Connect the cold water supply to the fitting marked ‘COLD’,
and the hot water outlet to the fitting marked ‘HOT’.
3. When attaching solder (sweat) fittings, DO NOT APPLY
HEAT DIRECTLY TO THE WATER HEATER NIPPLES
or the plastic liners will be damaged. Sweat adapters to the first
section of the water piping before threading onto the water
heater. Use a good grade of pipe joint compound that is
certified for use with potable water on the threaded fittings.
4. Install a manual shut-off valve in the cold water supply line. It is
good plumbing practice to include unions at the hot and cold
connections as shown. (Figure 5)
5. IMPORTANT: Before putting the water heater into service,
make sure that a properly rated and sized temperature and
pressure relief valve is installed in the designated fitting in the
water heater. See Temperature and Pressure Relief Valve
section below.
The relief valve is necessary to avoid excessive water pressure
or water temperature from developing. Such a condition could
cause serious personal injury due to scalding or serious
physical damage to the water heater. This safety device shall
be checked annually for proper operation. CHECK
LOCAL CODES!
6. With water piping installed, check that a hot water faucet
served by the water heater is open and that the heater drain
valve is closed. Open the cold water supply valve and fill the
water heater and piping system with water. When an
uninterrupted stream of water flows from the faucet, the system
is full. Close faucet. Check for leaks and repair as necessary.
7. Connect a hose to the drain valve and connect to drain.
Open drain and let water run until clear to flush out any
foreign matter that may have entered the system. Once
flushed, close the drain valve and disconnect hose.
NEVER OPERATE THE HEATER IF IT IS NOT
COMPLETELY FILLED WITH WATER.
FIGURE 4