John Wood Power Vent (Non-ENERGY STAR qualified models) - Manual (Page 7)

This gas piping must be installed in accordance with all local
and provincial or state codes or, in the absence of such, the
latest edition of "Natural Gas and Propane Installation
Code" CAN/CSA-B149.1 (Canada), or "National Fuel Gas
Code" ANSI Z223.1 (NFPA 54) (U.S.A.).
Use properly sized gas piping and to ensure full gas input
and a properly sized gas supply regulator to ensure ade-
quate gas supply pressure. The supply piping and regulator
must be large enough to satisfy the requirements of all
appliances connected to the gas service and when all appli-
ances are operating simultaneously. Undersize piping and
insufficient pressure can restrict the gas flow causing the
water heater to perform poorly. Improperly sized piping may
pose a safety hazard.
Note: When installing gas piping, apply sealing compounds
approved for use with natural and propane gas.
1.
Install a readily accessible manual shut-off valve in the
gas supply line as recommended by the local utility. The
owner/operator must be shown the location of this valve
and be given instructions on how to use it to shut off the
gas to the heater.
2. Install a drip leg (if not already incorporated as part of
the water heater) as shown. The drip leg must be no
less than 76mm (3 in.) long for the accumulation of dirt,
foreign material, and water droplets.
3. Install a ground joint union, or other approved gas dis-
connect, between the gas control/thermostat and the
manual shut-off valve. This is to allow easy removal of
the gas control/thermostat.
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 Supply Pressure
Important: The gas supply pressure must not exceed the
maximum supply pressure as stated on the water heater's
data plate.
Gas line purging
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 instal-
lation of the gas piping system.
Gas Leak 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 exceeding 14 in. w.c. (3.5 kPa), the water heater
and its manual shut-off valve must be disconnected
from the gas supply piping system and the line capped.
• If the gas lines are to be tested at a pressure less than
14 in. w.c. (3.5 kPa), the water heater must be isolated
from the gas supply piping system by closing its manu-
al shut-off valve.
Gas Operating Pressures
The gas supply pressure and burner manifold pressure is
listed on the data plate located on the front of the heater
above the gas control/thermostat. Ensure the gas supply
pressure to the water heater and the burner manifold pres-
sure are properly adjusted while all appliances are in oper-
ation. Refer to Figure 22 (Robertshaw) or Figure 24 (White-
Rodgers) for Gas Control/Thermostat Details.
U.L.and CSA recognized fuel gas and Carbon Monoxide
(CO) detectors are recommended in all applications and
should be installed using the manufacturer's instructions
and local codes, rules or regulations.
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.
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