Bosch WR430-7K - Manuel (Page 13)

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Check to make sure that the gas listed on the rating plate is
same as gas listed on the pressure regulator. See
PRESSURE REGULATION section of this manual for
information regarding gas pressure settings.
Note: Before attaching the gas supply line, be sure that all
gas pipe is clean on the inside. To trap any dirt or
foreign material in the gas supply line, a drip leg must
be incorporated in the piping. The drip leg must be
readily accessible and not subject to freezing
conditions. Install in accordance with the
recommendations of serving gas supplier.
Joint compounds (pipe dope) shall be applied sparingly and
only to the male threads of pipe joints. Do not apply
compound to the first two threads. The joint compound must
be resistant to the action of liquified petroleum gases.
Before placing water heater in operation, check for gas
leakage. Soap and water solution, or other material
acceptable for this purpose shall be used in locating gas
leaks. Matches, candles, lighters, or other ignition sources
shall not be used for this purpose.
WARNING
The heater and its individual shutoff valves must be
disconnected from the gas supply piping system during any
pressure testing of that system at test pressures in excess
of 3.45 kPa (1/2 psig).
The water heater, including the pressure regulator provided
with it, must not be operated at gas supply pressures in
excess of 3.45 kPa (1/2 psig). If overpressure has occurred
such as through improper testing of the gas lines or
emergency malfunction of the supply system, the gas valve
and regulator must be checked for safe operation. Make
sure that the outside vent valves are protected against
blockage. These are part of the gas supply system, not the
water heater. Vent blockage may occur during ice storms.
Figure 7 Gas Burner test point D for measuring burner
manifold pressure at full flow and input:
Standard Altitude: 4.58”W.C. Nat Gas, 9.11”W.C. Propane.
High Altitude: 3.73”W.C. Nat Gas, 7.27”W.C. Propane.
GAS CONNECTIONS
Before connecting the gas supply to the heater, check
heater’s model/rating plate to make sure that the gas on
which heater is to operate is the same as specified on the
model/rating plate.
The WR430-7.K.. instantaneous water heaters are supplied
with a gas pressure regulator that must be installed on the
heater before attaching the gas supply line. See figure 6.
Failure to install the gas pressure regulator as shown in
figure 6 will be a violation of A.G.A. and C.G.A. certification
of the unit.
BOSCH water heaters are shipped from the factory with
the gas pressure regulators preset for the gas shown on the
rating plate to the correct pressure:
• in Canada, for high altitude operation;
• in U.S.A., for standard altitude operation unless
specifically marked as a high altitude unit.
GAS INLET PIPE
PRESSURE TAP T
APPLIANCE PRESSURE
REGULATOR
Figure 6 GAS MANIFOLD PRESSURE TEST POINT
T For measuring correct regulator operating pressure.
Figure 7
RELIEF VALVE
The listed pressure relief valve supplied must be installed
near the hot water outlet at time of installation of the heater.
No valve is to be placed between the relief valve and the
heater. A drain line must be connected to the relief valve to
direct discharge to a safe location. Do not install reducing
coupling or any other restriction in the discharge line. The
discharge line must be installed so as to allow complete
drainage of both the valve and the line. See figure 5.
Figure 5