John Wood Superflue Power Vent (75 Gallon) - Manual (Page 9)

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 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 20 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.
Air Requirements
General
• An adequate air supply shall be provided for combus-
tion and ventilation of this water heater. An insufficient
supply can result in poor combustion and possible soot-
ing of the burner, combustion chamber or flue passage-
way. This may present a potential fire hazard or could
create a serious health hazard by producing carbon
monoxide.
Where an exhaust fan or any other air consuming appliance
(e.g., clothes dryer, furnace, etc.) is installed in the same
space as the water heater, sufficient air openings must be
available to provide fresh air when all appliances are oper-
ating simultaneously.
For buildings that are not well-sealed (do not have tight fit-
ting doors and windows) natural air infiltration may provide
sufficient air required for combustion and ventilation. For
buildings using tight construction (newer and renovated
structures), the air supply shall be introduced from the out-
doors, regardless of whether the space is confined or
unconfined.
Combustion Air “Supply” Ducts
Air supply ducts shall be of galvanized steel or equivalent
corrosion resistant material. A single air duct may not be
substituted when required for upper and lower air openings.
Horizontal combustion air ducts shall not slope downward
toward the air inlet.
Louvers and Grilles
Openings for air supply ducts must provide free unobstruct-
ed air movement. Louver and grille openings must be sized
to ensure that the FREE OPEN AREA is never less than the
area of the air duct.
– 9 –
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.
WARNING
Failure to properly install this heater may
result in a fire hazard.